Plumpton: Soil Flashcards
(708 cards)
1
Q
What is abstraction?
A
The process by which humans remove water from its source.
2
Q
Give three things that Triticum and Hordeum have in common.
A
- Nodal root system
- Rhizomatous
- Smooth, hairless, glossy leaves!
3
Q
What are the five main simple leaf shapes?
A
Note: truncate leaves have a flat base.
4
Q
What’s an angiosperm?
A
A flowering plant that produces seeds enclosed within a fruit.
5
Q
What does “light availability” refer to?
A
Remember that “light availability” refers not just to the presence of light, but also if it’s the correct wavelength and intensity. Some plants have pigments that can only absorb certain wavelengths!
6
Q
What do decomposer bacteria do?
A
They consume easy-to-digest carbon compounds and simple sugars and tie up soluble nutrients like nitrogen in their cell membranes.
7
Q
What is the formula for respiration?
A
C6H126O2 –> 6CO2 + 6H2O + ATP (released energy)
8
Q
What is the most abundant family of the vascular plants?
A
The grasses!
9
Q
Water (both liquid and vapor forms) binds to soil particles through two processes. Name these two processes.
A
- Adhesion
- Absorption
10
Q
Do pollen tubes only grow on conspecific stigmas?
A
Yes - the stigmas have recognition proteins.
11
Q
What do palisade cells have really high levels of?
A
Chloroplasts!
12
Q
Igneous rocks are classified into two groups depending upon ______________________________.
A
Igneous rocks are classified into two groups depending upon where the molten rock solidifies.
13
Q
The type of cloud that forms usually depends on what two things?
A
- The height of the cloud
- The condensation nuclei (e.g., pollen and/or dust).
14
Q
Give five reasons as to why you would use a soil alternative (e.g., hydroponics and hydroculture).
A
- Better Yields
- Quicker Growth
- Lower incidences of disease
- Less water wastage
- Control of nutrients
15
Q
- What’s the bract on a flower?
- Where’s it located?
- How do they look?
- What’s it used for?
A
- Specialised /modified leaf associated with the reproductive structure.
- One layer lower than the Sepal.
- Typically look different from the parts of the flower.
- Sometimes used for protection, sometime for attracting pollinators.
16
Q
What’s the difference between granular and crumb peds?
A
Granular peds are small with rounded surfaces. Crumbs peds are similar but slightly larger.
17
Q
What’s the only part of a yew tree that isn’t toxic?
A
The arils.
18
Q
Stems have cells that produce new living tissue. What are they called? How often do they generate new tissue?
A
- Meristems
- They generate new tissue annually
19
Q
When does soil compaction occur?
Involves some sort of critical moment and some sort of limit.
A
It occurs when the soil is sheared or compressed at the critical moisture content, known as the plastic limit.
20
Q
Why does increasing temperature increase the rate of evapotranspiration?
A
Evaporation and diffusion are faster at higher temperatures.
21
Q
Give three properties of soils with high organic matter content.
One’s to do with water, one’s about how it feels between your fingers, last is a reservoir of sorts…
A
- Soils high in OM retain more moisture.
- They have a crumbly structure that resists soil compaction.
- They contain a reservoir of nutrients that are slowly released over time.
22
Q
What are the three main causes of poor soil aeration?
A
- High soil moisture due to poor infiltration or over irrigation
- Soil compaction
- Over application of organic matter
23
Q
Label this diagram of a spikelet.
A
24
Q
Each piece of pollen creates its own…
A
Pollen tube.
25
What is an axil?
The joint between a stem and a leaf petiole.
26
What is the vascular bundle?
The centre of a root cyclinder that contains xylem and phloem.
27
How many different soil textural classes are there? How are they represented?
There are 12 classes!
28
What is the fifth and final stage of mitosis? What's the final result?
* The cell will completely divide in to two daughter cells as the cytoplasm and cell membrane separate.
* Each daughter cell will be identical to each other and their parent cell. Each daughter will have one nucleus, a complete set of DNA, and a set of organelles and the same amount of cytoplasm as their twin sister cell.
## Footnote
Cytokinesis (occurs at the same time as the telophase).
29
Are birch trees monoecious or dioecious? When do they flower?
* Monoecious.
* They generally flower between April and May.
30
What does it mean if a plant is vascular?
The plant contains xylem and phloem.
31
What can be found amongst phospholipids in a bilayer (not proteins)?
Cholesterol
32
How many leaflets are found on an ash leaf?
Between 4 to 7 (including the terminal leaflet).
## Footnote
Remember that elder leaves have less leaflets, usually only 5.
33
What's erosion?
* Once small pieces of rocks are changed or broken apart by weathering, they may start to be moved by wind, water, or ice.
* When the smaller rock pieces (now pebbles, sand or soil) are moved by natural forces, it is called erosion.
34
What are the two and a half main drawbacks of deep water culture hydroponics?
* It only really works for water-loving plants.
* Doesn’t work as well with larger plants or plants with long growth cycles.
35
What's the point of sepals/calyx when a flower is open?
To protect and support a corolla.
36
What does soil compaction increase and what does it decrease?
* It increases soil strength
* It decreases soil porosity
37
Give three things that can alter the pH of soil
## Footnote
Three processes
* Rainfall
* Fertilisation
* Decomposition
38
Where does light dependent photosynthesis occur?
In the thylakoid membrane.
39
What are the three different types of autochory?
* Gravity
* Blastochory (seed dispersal via offshoots)
* Ballochory (also called explosive dehiscence)
40
What is the definition of biological/Darwinian fitness?
The ability to survive to reproductive age, find a mate, and produce offspring.
41
What is the uppermost part of a grass called?
The flag leaf!
42
What happens to the outer layer of an ovule once it becomes fertilized?
It becomes lignified and forms a seed coat/testa.
43
Water has the highest surface tension of any known liquid. True or false?
True! It has a surface tension of 72.8.
## Footnote
This enables capillary action.
44
Where does light dependent photosynthesis occur? What does it produce?
Within the thlyakoid membranes/granums (remember that this is where chlorophyll is found). It produces ATP.
45
How are spruce trees pollinated?
Through anemophily (wind pollination).
46
What is water potential?
It's a measure of free-moving water molecules within a solvent. The less solutes dissolved in a solvent, the higher the water potential is.
47
What is leaching? What does it result in?
* Leaching is where excess fertilizer may be washed into lakes, streams, and rivers by surface runoff.
* Causes eutrophication: the overgrowth of algae and microorganisms no longer limited by the availability of nitrogen and phosphorus.
48
Where does light independent (dark) photosynthesis occur? What does it produce?
* It occurs in the stroma (the cytoplasm of the chloroplast).
* It produces NADPH.
49
What does a water molecule look like? What are the charges on the oxygen and hydrogen atoms?
50
Give three ways in which ballochory/explosive dehiscence can occur.
* Through osmosis
* Through dehydration (As the seed pod dehydrates, it tightens and is projected outwards. Seeds are dispersed without any external interference. It takes a lot of effort to do this).
51
When water freezes, it forms a _______________ structure with each water molecule ______________ bonded to _________ other water molecules.
When water freezes, it forms a crystalline structure with each water molecule hydrogen bonded to four other water molecules.
52
What's the first thing to develop inside a fertilized ovule?
Cotyledon(s).
53
Give two sources of irrigation water.
Water recycling
* Waste water from domestic homes or prior irrigation is filtered, treated, and re-used.
Rain capture
* Rain water is captured and stored for when it's needed. It's then pumped to plants (or carried to them by gravity).
* Or the soil is shaped to collect and store water near the plants themselves
54
What happens to proteins that are modified by the golgi apparatus? (2 Points).
* Modified proteins may remain within the golgi apparatus.
* They may also be packed into vesicles and sent off somewhere.
55
Give three examples of dioecious angiosperms?
* Asparagus
* Willows
* Cannabis
56
A plant has...
* Stunted growth
* Necrotic leaf tips
* Is yellow from a lack of chlorophyll...
What element does it desperately need?
Sulphur!
57
* What's the endodermis?
* What's its purpose?
* A layer of cells behind the cortex
* It regulates the flow of materials between the cortex and the vascular tissues
58
A plant has...
* Yellow leaf edges with brown patches.
* Its fruit also tastes awful...
What element does it need?
Potassium!
59
Name the three classifications of soil water.
* Hygroscopic
* Capillary
* Gravitational
60
If a seed is dispersed by endozoochory, what will it possess?
A thick seed coat/testa. Germination is enhanced as it's weakened by acid.
61
Name three elements that plants obtain from water and the atmosphere.
* Carbon
* Hydrogen
* Oxygen
62
Give four things that can cause chemical weathering.
1. Carbon dioxide
2. Oxygen
3. Water
4. Acids
63
How are evergreen branches oriented?
They're typically oriented downwards so that snow falls off of them more easily (too much snow breaks branches).
64
Try to recall some of the features of wind pollinated plants and insect pollinated plants.
| Petals, nectar, stigma, stamen, and pollen.
65
What happens to nitrogen once its consumed by an animal (Two possible things)
* It will be incorporated into the animal's body
* Or it will be excreted as waste (e.g., urea in urine)
66
What's the plural of carpel?
Pistil
67
What do sepals form when a flower is closed?
A bud! They help to protect an embryonic flower from being damaged.
68
Within a fertilized ovule, the central cell is _______________ while the egg cell is _______________.
* The central cell is triploid (it has 3 sets of chromosomes).
* The egg cell is diploid (it has 2 sets of chromosomes).
## Footnote
I think the central cell develops into the fruit, while the egg cell develops into the seed?
69
There are dark patches between leaf veins. What element is required?
Magnesium!
70
What's the parent/C horizon?
The deposit at Earth’s surface from which the soil developed. It's made of partly weathered rock.
71
What percentage of the atmosphere is nitrogen gas?
78%
72
What's the optimal soil moisture range for most crops?
The optimal soil moisture range for most crops is typically between 50% and 75% of the soil's field capacity (the level of capillary soil). This provides a balance between ensuring adequate water availability for plant growth and preventing waterlogging.
73
Isotonic environments are very rare in nature. What happens if plants do grow in one?
Turgor pressure is slightly reduced and cells become flaccid.
74
What are the two main benefits of ebb and flow hydroponics?
## Footnote
It's versatile in some way, and it's economical!
* Versatile system that can be used with a variety of growing mediums.
* Ensures plants obtain **just enough** nutrients.
75
What is a soil amendment?
A soil amendment is any material added to a soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration and structure.
76
What is the golgi apparatus made of?
Folded bits of membrane.
77
Give four things that microtubules are involved with.
* Mitosis
* Cell motility
* Intracellular transport (transport within the cell)
* The maintenance of a cell's shape
78
Give two molecules that can pass straight through a phospholipid bilayer.
Oxygen and water (smaller molecules!)
79
What's being shown here?
Parallel (monocot) and reticulated (dicot) veins.
80
What are the three main types of porous/absorbent hydroponic medium?
* Rockwool
* Perlite/vermiculite
* Oasis cubes
81
Holly trees can make different types of leaves at the same time. What is this ability called?
Heterophylly
82
Why is acid rain bad?
Even though it doesn't harm humans, it enters freshwater ecosystems and harms wildlife (since organisms cannot adapt to the acidity).
83
Both the cell wall and cell membrane are semi-permeable. True or false?
True!
84
How are the leaves in a deciduous forest arranged?
In strata (e.g., canopy, understorey, shrub, and ground).
85
Are deciduous trees generally angiosperms?
Yes.
86
What's the receptacle on a flower? What does it connect?
* The thickened part of a stem from which the flower organs grow.
* Often enlarged to support the weight of the flower, or the fruit when it develops.
* Connects the pedicle or peduncle to the flower.
87
What are angiosperms?
They're flowering plants that contain seeds within fruits.
88
What's the female reproductive organ of a flower known as?
The carpel.
89
How large are silt soil particles/separates?
0.002 to 0.05mm.
## Footnote
The intermediate particles.
90
What's wind pollen like? What about insect pollen?
* Small, smooth and light. It also comes in copious amounts.
* Insect pollen is larger and sticky (they have little hairs). They're also described as "sculpted".
91
How can grasses resist droughts?
## Footnote
Thin cell walls allow grasses to do something, which has a good effect...
They are able to resist drought because they have thin-walled cells between the veins of their leaves which keep the leaves expanded under normal conditions but roll up the leaves to slow evaporation during a drought.
92
How can cells be specialised? (Three examples)
Cells can be specialised by having more mitochondria, chloroplasts, or they may have a more elongated shape.
93
Which of the three soil water categories is **not** available to plants?
Hygroscopic (because its water potential is too low).
94
How does a plant acquire a tasty cation from the soil?
* It must exchange the cation it wants for another one with an equal charge.
* They often use hydrogen ions (H+) that are dispersed from their roots.
* In cases where tasty cations have charges higher than one, then multiple hydrogen ions can be exchanged (e.g., 2 H+'s for a single Ca+2 ion).
95
Access to the fixed nitrogen allows the plant to produce _________ fortified with _________ that can be ____________________.
Access to the fixed nitrogen allows the plant to produce leaves fortified with nitrogen that can be recycled throughout the plant.
96
Give five things that are included in a phenotype.
* Appearance
* Development
* Behaviour
* Hormone levels
* Number of blood cells
97
Give three examples of chemical sedimentary rocks.
* Limestone (again - limestone is formed when minerals dissolve in water, and then the water evaporates, leaving the minerals behind as a layer of sediment).
* Flint (which is a variety of chert).
* Banded iron formations.
98
What's the difference between ectomycorrizae and endomycorrhizae?
* Ectomycorrhiza is a type of mycorrhiza in which the fungal hyphae wrap around the plant root and form a mantle, but do not penetrate the root cells.
* Endomycorrhiza is a type of mycorrhiza in which the fungal hyphae penetrate the root cells, but do not form a mantle.
99
Where are the vast majority of guard cells located on a leaf?
On the underside of it. Specifically, they are found among the lower epidermis.
100
What's the main thing that mitochondria produce? What do they need to do this?
* Adenosine triphosphate (ATP).
* They do this with the help of oxygen.
101
Is gravel a good hydroponic growth medium? What are the two main downsides? What do you have to do with it?
Generally, yes
* Usually fairly cheap, works well and is typically easy to find.
* Supplies plenty of air to the roots
* But it doesn't retain water, which means roots can dry out quickly.
* Its weight can make it difficult to handle.
* Gravel can easily be reused as long as it is washed and sterilized between crops. Also use heat, steam, bleach or hydrogen peroxide for cleaning.
102
What occurs during the first stage of mitosis? (4 Points)
* Chromosomes become visible as they condensate (they get shorter and thicker).
* Organelles called centrioles produce mitotic spindle move to opposite ends of the cell.
* The nuclear envelope disintegrates.
* The chromosomes are freed into the cytoplasm.
## Footnote
The prophase
103
What does the stigma mark the beggining of?
The beginning of the transmitting tract - a tissue enriched in an **extracellular (outside cell) polysaccharide matrix** that provides guidance and a physical path for the pollen tubes growing toward the ovules.
104
What's a leaf's midrib? What's its main purpose?
It's the rib that runs down the middle of the leaf. It adds strength.
105
Give three grass species that use the "spike" spikelet formation.
* Wall barley
* Perennial rye-grass
* Meadow barley
106
What exactly is pH?
* The amount (or lack of) hydrogen (H+) ions in a solution (or soil).
* The higher the number of Hydroxide (OH-) ions = higher pH (Alkalis).
107
What does this graph show?
Compensation points.
* Black line: respiration.
* Green line: photosynthesis.
* Y axis: time of day. The compensation points are when the black and green lines intersect (there are two of them).
* When the green line is above the black line, excess glucose is being produced. This is when starch is produced.
* When the black line is above the green line, there isn’t enough glucose to meet the demands of respiration. This is when starch is hydrolysed (broken down – at night!)
108
What are the symptoms of calcium deficiency? (Two things)
## Footnote
Poor growth of something, and dead somethings.
* Poor root growth
* Dead leaf tips
109
How do you do the gravimetric method for measuring soil water content? What's it's main upside (and downside)?
* Obtain a soil sample and record the sample weight
* Dry the sample in an oven at 105℃ periodically weighing it until it ceases to loose weight.
* Calculate the water content as percentage lost.
* Accurate but time consuming and laborious.
110
What's the level of capillary soil water known as?
Field capacity!
111
What's the normal lifespan of plant cells?
One to three years.
112
Why is ice less dense than water?
Because water molecules are further apart in ice.
113
How are birch, beech, and ash trees pollinated?
Through anemophily.
## Footnote
Remember that beech trees are mainly wind pollinated.
114
What is hydroponics? What does hydroponic liquid contain?
## Footnote
We're looking for five major elements (not the one beggining with C), and any minor elements...
* Hydroponics involves growing plants in a liquid growing medium solution.
* The nutrient solution is a balanced mix of five major nutrients (nitrogen, phosphorus, potassium, magnesium and sulphur) and a very low concentration of minor nutrients or trace elements; copper, boron, iron, manganese, molybdenum and zinc.
115
How big are ash tree roots?
* They extend 4 feet downwards.
* They can occupy and area as wide as 48 feet.
116
What percentage of flowering plants are monoecious angiosperms?
Four percent.
117
What are the three different types of igneous landscape?
* Sills
* Dykes
* Batholiths
118
What binds soil particles together to form aggregates?
Water!
119
In terms of their functionc cotyledons either ___________________ OR they __________________________________________.
Cotyledons either photosynthesise (dicots/epigeal germination) OR they provide nutrients from the endosperm (monocots/hypogeal germination).
120
What's notable about grass inflorescences that possess the "spike" formation?
They're sessile - this means that spikelets lack pedicels and their attached directly to the rachis (main stem bit of the inflorescence).
121
How are peds categorised?
By their shape. Here are five examples:
* Granuluar/Crumb
* Subangular blocky/Blocky
* Prismatic/Columnar
* Platy
* Single grain/structureless
122
What's capillary water? What's it the main source of?
Capillary water is water that is held in the **macropores** of soil (spaces between soil particles), and is the main source of moisture for plants.
123
What is the formula for photosynthesis?
6CO2 + 6H2O → C6H12O6 (Glucose) + 6O2
124
What makes up the bulk of a fertilized seed?
The cotyledon(s)!
125
Most soils have three major horizons. What are they?
A, B and C (Top soil, subsoil, and parent rock).
## Footnote
Note that O (The organic layer) may be absent.
126
What is the point of adding a soil amendment?
To make conditions better for roots to grow in.
127
If the female part of a flower is called the gynoecium, then the male part is called the...
Androecium!
128
What do male and female beech flowers look like?
## Footnote
Male catkins hang down. Female flowers are found in pairs inside "cups".
129
What are fungi that feed on dead animals and plants called?
Saprophytic fungi.
130
What do male and female spruce flowers look like?
* Male flowers consist of clusters of stamens, which turn from red to yellow in spring when laden with pollen.
* Female flowers are red, upright and oval, and tend to form at the top of the tree.
131
Does the light independent (dark) phase of photosynthesis use or create ATP and NADPH?
It uses them and turns them into ADP + Pi and NAPD+
132
What wavelengths does chlorophyll absorb? (Just the colours)
It absorbs reddish-orange waves and violent-blue waves. Green waves are reflected.
133
What does it mean if something is hypotonic? What about hypertonic?
* Hypotonic: a solvent has a low tonicity/concentration of solutes.
* Hypertonic: a solvent has a high tonicity/concentration of solutes.
134
What are the six main impacts of low soil water content?
## Footnote
For plants
* Reduced plant growth (e.g., reduced leaf SA)
* Wilting
* Malformed root and shoot growth
* Reduced photosynthesis
* Poor seed germination
* Reduced nutrient absorption and transportation
135
What part of a root performs cell division to produce new cells for the developing root?
The apical meristem (AKA the root tip, but not the root cap which is the true tip).
136
Does grass die during a fire?
During a fire, while above-ground portions of grasses may perish, the root portions survive to sprout again.
137
How do fibrous roots develop? What are they characteristic of?
* They begin life as a short-lived primary root.
* As the plant grows it develops more fibrous roots (a root crown).
* They’re characteristic of monocotyledonous plants.
138
What are the two main benefits of needle leaves?
Some trees have needles as they help to prevent water loss. Needles also help to prevent snow from building up.
139
How can gypsum be good for soil (two ways)?
* Gypsum can help break up compacted clay soils, making them more porous and able to absorb moisture. This can help with root development and nutrient absorption.
* Gypsum can help soil soak up water after precipitation, reducing runoff.
140
How can a soil's structure affect its water content?
## Footnote
More or less aggregated?
Well aggregated soils will hold more water.
141
What are six qualities of soil that affect water content?
## Footnote
Plus two bonus things!
* Texture
* Structure
* Organic matter
* Density
* Temperature
* Impermeable subsoils
## Footnote
Don't forget surface seals and hardsetting layers!
142
What are the symptoms of phosphorus deficiency? (Two things)
* Purple tinge to leaves
* Leathery feel
143
The shape of a leaf is normally due to _______________ and not ____________.
Its shape is often due to environment and not function.
144
Does respiration occur at certain times of the day within a plant?
No - respiration is constantly occuring within a plant.
145
What can be found next to phloem cells? (Name + 3 Points)
Companion cells!
* Transport of substances in the phloem requires energy.
* One or more companion cells attached to each sieve tube provide this energy.
* A sieve tube is completely dependent on its companion cell(s).
146
Give three SECONDARY plant macronutrients!
* Magnesium
* Calcium
* Sulphur
147
What are the symptoms of sulphur deficiency? (Four things)
## Footnote
A colour, leaves suffer from two conditions, and stunted...
* Yellow or pale green colouring throughout the plant
* Young leaves suffer from chlorosis (where leaves turn yellow due to a lack of chlorophyll)
* Leaf tips turns necrotic
* Stunted growth
148
Why do palisade cells have a funny shape?
They have an elogated shape to increase SA for photosynthesis + more chloroplasts!
149
What's alkalinity? Why is it important?
A measure of the ability of a solution to neutralize acids, important in determining soil pH and nutrient availability.
150
What's an upside and two downsides of epigeal germination?
* You can use light to sustain yourself
* However, shade means death :(
* Above ground cotyledons are also susceptible to predation
151
Do all dicots use above ground/epigeal germination?
No (but most of them do).
152
What is podsoliation?
The process by which the **upper layer of a soil becomes acidic** through the **leaching of bases** which are deposited in the lower horizons.
153
Give four examples of metamorphic rocks.
* Gneiss
* Quartzite
* Marble
* Schist
154
What's the difference between prismatic and columnar peds?
Prismatic: rectangular with a long vertical dimension and flattened top.
Columnar: rectangular with a long vertical dimension and rounded top.
155
What sort of barrier does the stigma possess?
An inter-specific incompatibility barrier (prevents fertilisation by interspecific pollen).
156
Imagine a hydroponics farmy.
## Footnote
Not drip irrigation.
157
What are glumes?
A pair of bracts at the base of a spikelet.
158
What are the two different types of zoochory?
* Endozoochory (digestion)
* Epizoochory (externally carried)
## Footnote
On a side note, dispersal by ants is called myrmechory.
159
How do you identify a female flower on a monoecious angiosperm?
Female flowers have a tiny fruit at the base, males don’t.
160
Do the cells of the root pericycle last long?
Yes, they last quite long indeed!
161
Who proposed th theory of evolution through natural selection?
Alfred Russel Wallace (not Charles Darwin!)
162
Where is the spongy mesophyll located? What's its main role?
* The spongy mesophyll is found below the palisade mesophyll.
* Its main role is gas exchange (there's lots of free space within it to help with this).
163
Sedimentary rock is purely abiotic. True or false?
False, it can be made of bits of dead organism (e.g., limestone).
164
What are ebb and flow hydroponics?
Ebb and Flow (or Flood and Drain) system works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into a reservoir.
165
What's a leaf's margin?
It's literally just the edge of the leaf.
166
Are beech trees monoecious? When do they flower?
Yes, they're monoecious. They flower between April and May.
## Footnote
Just like birch trees.
167
Where can starch be stored? What even is starch?
* Starch can be stored in the leaves, stem, and roots.
* Starch is glucose in storage form.
168
What does evapotranspiration create?
A vacuum/lack of pressure (9 atmospheres) that causes water to be pulled up.
169
What are the five different things that can cause weathering?
* Water
* Air
* Chemicals
* Plant
* Animals
170
What are dead, lignified cells called?
Wood!
171
What happens if plants can't create enough starch during the winter? (Two examples)
They may stop their growth or shed their leaves.
172
"Infiltration" is often used interchangably with what other word?
Percolation.
173
What's anaerobic respiration?
Respiration that occurs without oxygen, producing less energy and resulting in by-products like ethanol or lactic acid.
174
How is the "panicle" spikelet inflorescence arrangement defined?
"Primary axis bears branched secondary axes with spikelets **on pedicels**."
## Footnote
“Branched branches”.
175
What do plants use potassium for? (Four things)
* Flowering
* Fruit ripening
* Disease resistance
* Water regulation
176
What occurs during the fourth stage of mitosis?
* The chromatids reach opposite poles of the cell.
* Now, the chromatids uncoil and become long and thin again and can be called chromosomes again.
* The nuclear envelope reforms around the chromosomes. A nuclear envelope forms around each set of chromosomes – one on each pole of the cell. Therefore the cell now has two nuclei, each with a complete set of identical DNA.
## Footnote
The telophase
177
What do ash flowers look like? When do they appear?
Both male and female flowers are purple and appear before the leaves in spring, growing in spiked clusters at the tips of twigs.
178
Give four photosynthetic pigments that aren't chlorophyll a and b. What wavelengths do they reflect?
## Footnote
LBZL
* Lutein (Yellow)
* Beta-carotene (Orange)
* Zeaxanthin (Yellow)
* Lycopene (Red)
179
What's the most common type of hydroponics farm and how does it work? Is the system unique to hydroponics?
Drip irrigation (AKA slow feed systems)
* A timer controls a submersed pump.
* The timer turns the pump on and nutrient solution is dripped onto the base of each plant by a small drip line.
* Drip systems are not unique to hydroponics. Such a setup is also widely used in outdoor agriculture to deliver water and nutrients to individual plants and works equally well with soil as well as growing media.
180
How's vascular tissue arranged in a monocot stem? What about a dicot stem?
* In a monocot, vascular tissue is arranged sporadically.
* In a dicot, it's far more arranged and tidy.
181
What percentage of SOM do most soils have? What about cultivated soils?
* Most productive soils have between 3 and 6% organic matter
* Mineral soils form most of the world’s cultivated land and may contain from 0 to 30 percent organic matter.
182
Where is the endoplasmic reticulum located? What's it made of?
The endoplasmic reticulum shares part of its membrane with that of the nucleus. Its mainly comprised of water, salts, and proteins.
183
Name some soil micronutrients that plants need.
* Boron (B)
* Chlorine (Cl)
* Copper (Cu)
* Iron (Fe)
* Manganese (Mn)
* Molybdenum (Mo)
* Zinc (Zn)
* Nickel (Ni)
184
Is transpiration an active process?
No, it's a passive process.
185
Are expanded clay pellets expensive? Is this really an issue?
They are expensive, but they're one of the few kinds of media that can be easily reused by removing old roots and sterilising with bleach, steam, heat or hydrogen peroxide.
186
What's eluviation?
The sideways or downward movement of dissolved or suspended material within soil caused by rainfall.
187
What are biological sedimentary rocks? Give three different examples.
Biological sedimentary rocks form when living organisms die, pile up, and are then compressed and cemented together.
Types of biological sedimentary rock include:
* Coal (accumulated plant material that is carbon-rich).
* Limestone.
* Coquina (rocks made of marine organisms).
188
Wherever water goes (either through the air, the ground, or our bodies) things are dragged with it. Why?
Because of its polarity!
189
What is the role of ATP?
To store energy.
190
Give a diagram that shows the three different water types.
191
Transport in the xylem is a ____________________. It does not ____________________.
Transport in the xylem is a **physical process**. It does not **require energy**.
192
What's a pro and a con of anemophilous pollination?
* Pro: doesn't depend on insects
* Con: less targeted/pollen can get carried away by strong winds
193
Hazel nuts are tasty. How are dispersed?
* Some animals will stash them away.
* They'll then forget about them and the nuts will develop into new trees!
194
What's a culm? What is one made up of?
* A hollow and pithy grass stem.
* They're made up of internodes that are joined together by nodes.
195
What do multiple water molecules look like?
196
What sprouts from a taproot?
Secondary and tertiary roots.
197
Why does the spongy mesophyll layer exist?
Because palisade cells are tightly packed together, gases can’t get through them easily. This is what the spongy mesophyll layer is for.
198
What does semi-permeable mean?
It means that some things can pass through a membrane, while other things can't.
199
What can't fibrous roots support? Where can't they survive?
Anything that's too top heavy. They can't survive in thick soils (e.g., clay).
200
What are the three main sections of a cell?
* The cell membrane
* The cytoplasm
* The nucleus
201
Give four cons of using organic compounds
## Footnote
Less control, speed, price, related to the first one.
* There's less control over nutrient levels
* They tend to be slower acting
* They're quite expensive
* You need to mix multiple fertilisers to achieve the correct balance of nutrients
202
What's a leaf's apex?
Literally just the tip of a leaf.
203
What's the name of a grass's...
* Seed head
* Leaf
* Stem
* Seed head: Inflorescence
* Leaf: Lamina
* Stem: Culm
204
What percent of green plants are angiosperms?
Roughly 80% of all green plants.
205
What's hygroscopic water?
Hygroscopic water is a thin film of water that adheres to soil particles. It is absorbed from the atmosphere (meaning that's where it comes from).
206
What's an anther?
The part of a stamen that contains the pollen.
207
Fill in the rock cycle!
208
Describe coconut coir as a hydroponic growth medium.
## Footnote
What's it made of, why is it so good, how's the ratio, where would it go otherwise, what's its downside?
* Made from ground up coconut husks.
* Coconut nusk acts as a great growing medium for the coconut to germinate and create new trees.
* Great air to water ratio.
* Would generally go to waste or be composted if they weren’t used in hydroponic applications.
* Holds a lot of water and may drown plants.
209
What are the four different categories of hydroponic growth medium?
* Large particle material
* Fibrous material
* Porous and absorbent material
* Composted or aged material
210
What do xerophytic plants' mesophyll cells do to their food?
In xerophytic plants, mesophyll cells store water and food in soluble forms.
211
How do igneous rocks form?
## Footnote
Cooling can be divided into two processes...
Igneous rocks form when hot, molten rock (magma) crystallizes and solidifies.
212
What are tubers? Give a classic example.
* Storage organs that are modified stems.
* They're horizontal and they grow above the root crown.
* Potatoes are a classic example.
213
What determines a clay soil particle's cation exchange capacity?
* Its charge (e.g., how negatively charged it is so it can hold onto cations).
* Its surface area (so there's more space for cations to bind).
214
What are the four different types of leaf margin? What's a key difference between two of these?
Entire, toothed, lobed, and parted.
## Footnote
If a midrib goes more than halfway up a stem, then it’s parted. If it doesn’t, it’s lobed (I think).
215
What causes precipitation to occur? What bonus thing is required?
## Footnote
Name two different processes.
* When the tiny condensation particles grow too large, **through collision and coalescence, for the rising air to support**, and thus fall to the earth.
* Precipitation requires tiny water droplets to condense on even tinier dust, salt, or smoke particles, which act as a **nucleus**.
216
Do chalky soils have a high or low pH?
They have a high pH (they're alkaline).
217
What is found at the very tip of an epicotyl?
The plumule (which develops into the shoot!)
218
Why is stopping photosynthesis good for a thirsty plant?
Because it uses water. When water levels run low, guard cells close and photosynthesis stops (no CO2 entering the plant!)
219
What happens to female beech flowers as they mature?
The cup becomes woody once pollinated, and encloses one or two beech nuts (known as beechmast).
220
What are aeroponics? What's its main downside?
* Probably the most high-tech type of hydroponic gardening.
* The roots hang in the air and are misted with nutrient solution. The mistings are usually done every few minutes.
* A timer controls the nutrient pump much like other types of hydroponic systems, except the aeroponic system needs a short cycle timer that runs the pump for a few seconds every couple of minutes.
* Because the roots are exposed to the air, they will dry out rapidly if the misting cycles are interrupted.
221
Two things get fertilized inside a plant ovule. What are they?
* The central cell gets fertilized by one sperm
* And the egg cell gets fertilized by another sperm
222
Water has very high solvent power. What does this mean? (3 Points)
* More things can dissolve in it than anything else. It is referred to as a universal solvent.
* This is because water’s polarity allows it to attract other polar molecules, like glucose.
* It’s also why oil won’t mix because it’s not polar.
223
Give four cons of using inorganic fertilisers
* Their production creates environmental damage
* They contribute to groundwater pollution
* They contain salts that can burn plants
* You need to mix multiple fertilisers to achieve the correct nutrient balance (just like organic fertilisers)
224
Are hollies dioecious or monoecious?
They're both!
225
What's the carpel also known as (not its plural).
The gynoecium.
226
What are the symptoms of potassium deficiency? (Two things)
## Footnote
Taste related, and a certain leaf part turns into certain colours (2 to be exact) - think of bananas.
* Yellowing on leaf edges, followed by brown patches
* Fruits will have a poor flavour
227
Phloem cells have large __________ which join to the __________ in the next phloem cell to make a _______.
Phloem cells have large **vacuoles** which join to the **vacuoles** in the next phloem cell to make a **tube**.
228
What factors can affect seed viability/the capacity of a seed to produce a seedling that can reproduce if everything goes well? (4 Points)
* The ability of the mother plant to produce viable seeds
* Predator and pathogen damage
* Environmental conditions like flooding or heat
* The age of the seed also affects its health and germination ability.
229
A flowering plant that possesses both male and female flowers is called a what?
A monoecious angiosperm!
230
What are stolons? What are they also known as?
* Stolons are above ground, horizontal stems with nodes, internodes, and leaves.
* They're also known as "runners".
231
Each phloem sieve tube has a ____________________ end so its _________________ connects ____________________.
Each phloem sieve tube has a **perforated** end so its **cytoplasm** connects **one cell to the next**.
232
When do yew trees flower? Are they monoecious or dioecious?
* They flower between March and April
* They're dioecious
233
Soil structure is comprised of different layers **(called horizons)**. What are these different horizons called?
**OAEBCR**
* O: Organic layer (humus)
* A: Topsoil (minerals with humus)
* E: Eluviation layer (leached minerals and organic matter)
* B: Subsoil (deposited minerals and metal salts)
* C: Parent rock (partly weathered rock)
* R: Bedrock (unweathered parent rock)
## Footnote
Oh, An Enormous Baby Cute Rat...
234
What does cytoplasmic mean?
It means that something relates to the interior of a cell.
235
What's more important to plants: water or nutrients?
Water. Without it, nothing can get to where it needs to be within the plant.
236
What are stomata (singular: stoma) surrounded by?
Guard cells!
237
What's the most basic type of hydroponics? Why's it called that?
Deep water culture
Called Deep Water Culture for two reasons.
* One, you typically grow with a reservoir that can hold a decent amount of water.
* Two, because of how much of the root mass you submerge in the water. In deep water culture, most of your plant’s root system is submerged 24/7
Floating mats suspend the plants with their roots directly in a nutrient solution. An air pump supplies oxygen to the solution.
238
Give four things that improve in a soil when you add organic matter to it.
* Aeration
* Water drainage
* Root growth
* Biological activity
239
What happens when a plant grows in a hypertonic environment?
Water gets removed from cells via osmosis. Cells then shrink and lose turgor pressure.
240
Give six management practices that can help overcome restrictive soil layers.
Maintaining stubble cover.
Organic matter application.
Gypsum application.
Pasture phase.
Minimising traffic.
Rotation with deep-rooting crops.
241
When does surface run-off occur?
* Whenever the precipitation rate is greater than the infiltration capacity, surface runoff occurs.
* Surface Runoff occurs when there is excessive precipitation and the ground is saturated (cannot absorb any more water).
242
What occurs during the third stage of mitosis?
* The spindle fibres begin pulling the sister chromatids away from each other to opposite poles of the cell. This breaks the centromeres of the chromosomes.
* This splits each chromosome into two V-shaped sister chromatid structures.
## Footnote
The anaphase
243
What are a bunch of petals collectively known as?
The corolla.
244
What's mechanical weathering? What five things can cause it?
* Mechanical weathering is the process of breaking a large rock into smaller pieces without changing the minerals in the rock.
* Mechanical weathering may be caused by:
* Frost
* Ice
* Plant roots
* Running water
* Heat from the sun.
245
What do plants use calcium for? (Two things)
Calcium is for structural purposes in the cell walls and membranes, basically to keep cell walls together, and also other for metabolic functions.
246
What is a grass leaf ligule?
Membrane-like tissue on the inner side of the collar.
247
What sort of soils need to be fertilised more often?
Soils with low CEC (cation exchange capacity). Remember that the higher a soil's CEC, the more nutrients it can hold at any given time.
248
What are oasis cubes? What are they made from and when are they often used?
Cubes made from rock that has been melted and spun into fibrous cubes and growing slab. Plants sit in them.
* They're rigid, open-celled, water-absorbing pieces of foam specifically designed for **optimal callus** and **rapid root formation**.
* Made from phenolic foam, oasis cubes are most often used as a rooting media in commercial floriculture and make a great medium for starting seeds and cuttings in hydroponic production.
249
When is starch used?
When photosynthesis can't take place.
250
Why does sand make so a bad hydroponic growth medium?
* It has low water-holding capacity
* It has a tendency to pack tightly together, reducing the amount of air available to roots
## Footnote
Sand is the oldest known hydroponic medium.
251
Cytoplasm has form and structure. True or false?
True - it’s highly organised. A framework of protein scaffolds called the cytoskeleton provides the cytoplasm with its structure.
252
Is soil acidification a natural process?
Yes, but it's sped-up by intensive agriculture.
253
How can seed viability be assessed through looking at its texture? (3 Points)
## Footnote
How much space should be filled, what colour, how should it feel, and what three things should be identifiable?
* A cut test is performed where a seed is cut in half so that the contents inside can be assessed.
* Viable seeds will usually fill all the space inside the seed coat, be white in colour, feel firm, and the embryo of the seeds usually identifiable form the endosperm or starch supply.
* This will kill the seed :(
254
What two types of fertilization occur when a pollen tube extends into an ovule?
* The actual seed itself is fertilized by one gamete.
* The other gamete either fertilizes the central cell to create a fruit (in dicots) or a seed's endosperm (in monocots).
255
How do animals and plants release carbon through cellular respiration?
* Animals - they breathe out CO2
* Plants - they transpire it through their stomata
256
Why is chlorophyll green?
Because it reflects green light - all other waves are absorbed. Remember that green waves need to come into contact with your eyes in order for you to perceive them.
257
Are all deciduous trees dioecious?
No, you get a mix of monoecious and dioecious trees.
258
What sort of root system do almost all dicots have?
Tap root systems.
259
What are clastic sedimentary rocks? What are clasts larger than 2mm called?
## Footnote
Begins with a P...
* They're made up of pieces (clasts) of pre-existing rocks loosened by weathering.
* They have particles ranging in size from microscopic clay to huge boulders; their names are determined by the clast or grain size.
* Smallest grains/clasts are called clay, then silt, then sand.
* Clasts larger than 2 millimeters are called pebbles.
260
What are the three main advantages of self-pollination?
* It's not dependent on pollinating agents.
* If a given genotype is well-suited for an environment, self-pollination helps to keep this trait stable in the species.
* Number of flowers are small or widely spaced.
261
Give five factors that affect soil health.
## Footnote
NBFLO - Never Bite Funny Looking Ookies - because they're unhealthy!
* Nitrogen cycle.
* Bacterial activity.
* Fungi.
* Living Organisms.
* Organic Matter.
262
* Where is a root's cortex?
* What's its main purpose?
* What's it made of?
* Located on the inside of the epidermis.
* The cortex of herbaceous dicot roots is composed mostly of loosely packed parenchyma cells.
* The primary function is the storage of starches.
263
What are three main ways in which leaves can be arranged on a stem?
Alternate, opposite, and whorled.
264
Fertilisers add salts. How can salts affect plants?
* Salts can burn plants
* Too many soluble salts can also cause leaves to wilt and turn yellow
265
When water enters a plant cell, it pushes against the cell membrane (which pushes against the cell wall). What does this create?
Turgor pressure (and turgidity).
266
What are the symptoms of magnesium deficiency? (One thing)
Dark patches between the leaf veins
267
What is the cytoiskeleton?
* The cytoskeleton is a network of protein filaments.
* It also contains microtubules.
* Another component is actin. Filaments that are made of actin are responsible for positioning the organelles within a cell.
268
What is the infiltration rate of a soil?
Infiltration rate is the amount of water that enters the soil in a specified time period.
269
What is a sessile leaf?
A leaf with no petiole. Grass blades are counted as sessile leaves.
270
What does pH actually stand for?
Potential of Hydrogen
271
What is mulch?
Actively decomposing plant material.
272
What can a plant stem be divided into?
## Footnote
What three things can grow from nodes?
Nodes and internodes.
* The nodes hold one or more leaves, as well as buds which can grow into branches (with leaves, conifer cones, or inflorescences (flowers)). Adventitious roots may also be produced from the nodes.
* The internodes distance one node from another.
273
What are ribosomes? What are the five places where you can find them?
Ribosomes are organelles that synthesise proteins.
* They’re found in the cytoplasm
* The rough endoplasmic reticulum
* The nucleus
* Mitochondria
* Chloroplasts
274
What's SOM?
Soil Organic Matter
* Soil organic matter is the fraction of the soil that consists of plant or animal tissue in various stages of breakdown.
* On the basis of organic matter content, soils are characterized as mineral or organic.
275
What organelles do xylem cells contain?
* A nucleus
* A vacuole that joins to other xylem vacuoles to create a tube
* That's it!
276
Amount of hygroscopic water varies _______________ with the size of the _________________. Finer textured soils with high __________________ will absorb and hold far more hygroscopic water than ___________________.
Amount of hygroscopic water varies **inversely** with the size of the **soil particles**. Finer textured soils with high **clay content** will absorb and hold far more hygroscopic water than **coarse, sandy soils**.
277
What does a single ovule develop into once it's fertilized?
A seed.
278
What does the secondary cell wall do?
The secondary layer provides physical and chemical defence!
279
Name two different modified grass stems.
* Stolons
* Rhizomes
## Footnote
**Both** possess internodes and nodes.
280
Is seed dormancy common? What's the point of it? What two components are involved in dormancy?
* Yes, seed dormancy is common.
* It allows plants to hold-off germination until conditions are suitable. This gives plants the best chance at life.
* Normally some genetic component involved, but the environment plays a large part as well.
281
What do cotyledons do in epigeal/above ground germinated plants?
They develop chloroplasts and turn green, allowing them to provide energy for the rest of the plant.
282
It is said that each soil horizon tells its own...
Story.
283
Give two minor benefits of being a grass.
* Your soft stem allows you to bend in the wind.
* It also allows you to take advantage of anemophily.
284
What does chlorophyll do?
It uses light to split CO2 into O2. It also splits H2O into H2 and O.
285
Nitrogen is found in all ___________ and ______.
Proteins and DNA.
286
What's the nucleolus?
A large spherical structure within each nucleus. It’s responsible for the creation of ribosomes.
287
Give two ways in which organic matter can be mixed into soil
* Manually (e.g., with machinery)
* Soil organisms can mix-up the soil, though this requires an abundance of organisms and low run-off risk
288
What's the sepal on a flower?
* Green parts that surround and protect the flower bud and extend from the base of a flower after it has opened.
* Support the petals once in bloom.
* Size and shape varies with species.
289
What cycle occurs within the mitochondria?
The Krebs cycle (AKA the tricarboxylic cycle). It creates by-products that mitochondria use to generate energy.
290
There are two different types of parenchyma ground cell. What are they? (Just their names)
* Chlorenchyma
* Aerenchyma
291
What's the E/eluviated horizon? Is it present in all soils?
## Footnote
Three things get leached (one is a soil separate, the other two are more generic), meaning two things get left behind...
* Leached clay, minerals, and organic matter, leaving a concentration of sand and silt particles of quartz or other resistant materials .
* Missing in some soils but often found in older soils and forest soils.
292
As the hydrogen bonds that form between water molecules are so weak, water is an __________________________________________________.
Water Is an aggregate of H2O molecules reforming and reattaching constantly.
293
* What is a root's epidermis?
* What is its main function?
* What does it generate?
* A skin of cells covering the surface of the root.
* Where the water and minerals enter the root through osmosis and diffusion.
* Generates distinctive growths, or hairs, called trichomes.
294
* What percentage of SOM consists of live organisms?
* What percentage of it is decomposing/decomposed organic matter?
* 5% of SOM = live organisms.
* 95% of SOM = decomposing organis matter (detritus) and decomposed organic matter (humus).
295
What's soil solvent?
Water! (The carrier of nutrients for plant growth!)
296
Why do compound leaves exist?
Compound leaves exist because large, tall trees want to avoid having large, singular leaves. This is because they’re prone to wind damage (the tree may even fall over). Compound leaves are more wind resistant and don’t act like sails.
297
What do plants use sulphur for? (The formation of five things)
The formation of...
* Amino acids
* Proteins
* Oils
* Chlorophyll
* Nodules in legumes
298
What do ribosomes contain?
A sub-unit of RNA.
299
What's seed viability? (2 Points)
* A seed's capacity to germinate and produce a normal seedling.
* It's a measure of how many seeds are alive and could develop into plants which will reproduce themselves, given appropriate conditions.
300
What does the golgi apparatus do?
It modifies proteins. More specifically, the golgi apparatus scans a protein’s amino acid chain for special codes. The protein is then modified accordingly.
301
What is relative humidity?
Relative humidity is a percentage of the amount of water vapor present in the air in relation to the total amount it can hold at that temperature.
302
Give two ways of increasing soil pH
* Liming (adding material that contains lime)
* Wood ash can also be used as they contain high levels of potassium and calcium (phosphate and boron as well)
303
What's the difference between detritus and humus?
* Detritus is decompos**ing** organic matter
* Humnus is decompos**ed** organic matter.
304
What are parenchyma ground cells? Give some examples of tissues that are made of parenchyma cells.
* Parenchyma cells are "basic cells".
* They form the bulk of plant tissues (e.g., soft parts of leaves, fruit pulp, and other plant organs).
305
What do female ash flowers develop into once pollinated?
* Once pollinated, female flowers develop into conspicuous winged fruits, or 'keys', in late summer and autumn.
* They fall from the tree in winter and early spring, and are dispersed by birds and mammals.
306
What's a venule? Why can't they be the size of veins?
* They’re little veins that are the leaf equivalent of capillaries.
* They extend from leaf veins.
* If all venules were the size of veins then there would be no space for photosynthesis.
307
Why are palisade cells packed tightly together?
Palisade cells are packed together because cells and the organelles within them die frequently. If you had one long giant cell then it would be inefficient and vulnerable.
308
Is air/gravitational water useful to plants?
It's of little use to plants as it drains away quickly and fills the macropores of the soil, reducing aeration.
309
Fertilisers raise salt concentrations. Why is this bad?
## Footnote
For tiny beings.
Salt levels may be raised to a level that's fatal to microorganisms.
310
What exactly are inorganic fertilisers? Give two examples of them.
* They're synthetic, artificial forms of plant nutrients.
* Ammonium sulfate
* Ammonium phosphate
311
Does carbon form molecules easily?
Yes, it very readily combines with other elements to form molecules. This is despite the fact that it lives in nearly pure forms, like diamond and graphite.
312
Give six ways in which soil health can be managed.
* Fertilisation.
* Adding organic matter.
* Aeration.
* Irrigation.
* Ph adjustment
* Drainage
313
What are grass ""flowers"" called? How are they put together?
Spikelets!
* They're groups of flowers
* Individual flowers are called florets
* Florets are made up of palea and lemma.
314
What do spongy mesophyll cells do in aquatic plants?
They form aerenchyma so leaves can be buoyant!
315
At what point does SOM decline within soil
When the rate of addition is less than the rate of decomposition.
## Footnote
And vice versa.
316
Sedimentary rocks are classified into three main groups. What are they?
Clastic, Biologic, and Chemical.
317
How are xylem cells structured?
They're structured like a tube. Multiple xylem cells stack on top of each other and their vacuoles join together to form long, hollow tubes.
318
Name the two main ways of measuring soil water content.
* Gravimetric
* Conductivity
319
What percentage of all **fresh**water is stored in ice?
68.7%.
## Footnote
This is only 1.74% of all water.
320
What sort of root system do pretty much all monocots have?
Fibrous root systems.
321
What are the products of respiration?
* Chemical energy
* Water
* CO2
322
What holds capillary water in place (two things)?
* Capillary water is held in place by water's cohesive bonding properties and capillary action.
* It's bonded to the hygroscopic water surrounding the soil particles and held within micropores inside soil particles.
323
What is a thylakoid membrane? What's a stack of thylakoid membranes called?
* A thylakoid membrane is a little disc.
* A stack of little discs is called a granum.
324
Why does divergent evolution occur?
Populations get physically split apart (e.g., Grand Canyon) preventing the sub-populations from interacting.
325
Other than the leaves, where else can chloroplasts be found? Where won't they be found?
They're found in the stem. You won't find them in the roots.
326
Give an example of a photosynthetic organism that isn't green.
Marine algae
* This is because long, red wavelengths are reflected and absorbed by water within the first 30 feet of water.
* Therefore, it's best for them to absorb green wavelengths (instead of reflecting them).
327
What are the two regions of the endoplasmic reticulum?
The rough bit and the smooth bit.
328
How does leaching work?
* As water passes through the rock and soil, it interacts with the surfaces of the materials.
* Compounds on the surface of minerals become dissolved and carried with it.
329
X-rays can be used to find viable, healthy seeds without killing them. What's the main downside of X-rays?
They're expensive :(
330
Give two different types of mutualistic bacteria that form relationships with plants.
* Nitrogen-fixing bacteria
* Actinomycetes (bacteria that form inside mycorrhizae).
331
What positions organelles within a cell?
The cytoskeleton (specifically actin filaments).
332
What are awns?
Extensions of grass lemmas that form slender, stiff bristles.
333
Give three lesser forms of organic matter.
* Peat
* Fertiliser
* Sewer sludge
334
What are the two main reticulated leaf venation patterns? What's the main difference between the two?
The difference between pinnate and palmate leaves is that pinnate leaves have a central vein – palmate leaves do not.
335
Why do plants require heat?
Because they cannot generate it on their own. They need it for enzymes to function.
336
What's nitrogen fixation?
Where bacteria convert N2 from the atmosphere into ammonia (NH3), a form of nitrogen that's usable by plants.
337
Do expanded clay pellets work well as a growth medium?
Yes, they work extremely well as a growing medium.
## Footnote
They meet the four main criteria.
338
How does low soil water content affect seed germination?
Many seeds **require water to soften the testa** and allow oxygen to penetrate and allow respiration, as well as allowing the hypocotyl to break through. This won't happen if there's not enough water.
339
Spruce cones are semi-serotinous. What does this mean?
Semi-serotinous means that cones are partially sealed shut and need heat to fully open.
340
What mechanism ends seed dormancy?
A hormonal response!
341
What's the cambium in a root cyclinder? What's it responsible for?
## Footnote
It's responsible for the secondary growth of ______ and ______.
A layer of actively dividing cells between xylem and phloem tissues that is responsible for the secondary growth of stems and roots.
342
What do beech leaves look like when they're young?
They start off furry :3 The fur is lost and they get older (they also become less lime-coloured and more dark).
343
Root hair cells are __________-celled extensions of __________________ in the root. They grow between soil particles and ___________________________ from the soil.
Root hair cells are **Single**-celled extensions of **epidermal cells** in the root. They grow between soil particles and **absorb water and minerals** from the soil.
344
What are the five phases of mitosis? (Just name them)
* Prophase
* Metaphase
* Anaphase
* Telophase
* Cytokinesis
## Footnote
Please Masticate A Tasty Carrot
345
What does the primary cell wall do? How does it do it?
It connects the cell to other cells. It does this by conjoining with the middle lamella which cements cells together.
346
What is the formula for photosynthesis?
6CO2 + 6H2O --> C6H12O6 + O2
347
What's the difference between subangular block and blocky peds?
* Subangular blocky: cube-like with flattened surfaces and rounded corners.
* Blocky: cube-like with flattened surfaces and sharp corners.
348
A plant has...
* Funny, stunted roots.
* It leaf tips are also dying.....
What element is required?
Calcium!
349
What are the by-products of photosynthesis and respiration?
* Photosynthesis: oxygen
* Respiraton: CO2
350
Water enters the soil through ________________ (_______________) and is stored in many __________ (_____________).
Water enters the soil through **large pores** (**macropores**) and is stored in many **small pores** (**micropores**).
351
What is the "cytoplasm of the chloroplast" called? What's it made of?
The stroma. It's made of water and salts.
352
What are aerenchyma?
* A type of parenchyma ground cell.
* They're only found in some species.
* Aerenchyma tissue contains air pockets - some cells are lost as a result.
* They provide buoyancy in aquatic plants.
353
What are some easy ways to tell the difference between *Triticum* and *Hordeum*?
* Barley (*Hordeum*) has really long awns. *Triticum* species (wheat) lack awns.
* Barley auricles are long and they overlap. Wheat auricles do not overlap.
* Barley auricles are hairless. Wheat auricles have hair.
354
The vacuole of the root hair cell ______________________________.
The vacuole of the root hair cell **stretches into the root hair**.
355
What is plantae?
A **kingdom** which contains all plants.
356
What's the easiest way to assess seed viability? What do you need to remember?
By growing seeds, of course! Remember: seeds that do not germinate are not necessarily dead, but possibly dormant and this needs to be considered in the results.
357
What's gleyling?
A technical term that describes the gray, blue, purple or green soil colors that occur in soils that have been waterlogged for prolonged periods of time.
358
What enables capillary action?
Water's very high surface tension.
359
What sort of flowers have petals in threes?
Monocots!
## Footnote
Dicots have four or five petals.
360
What are two obvious features you can use to differentiate a monocot from a dicot?
Monocot left, dicot right.
361
Give three very broad categories of elements that are required by plants for growth.
* Elements from Water and the Atmosphere
* Macronutrients
* Micronutrients (Trace elements)
362
What is exosmosis?
Osmosis, but where the solvent (water) moves from a high solute concentration to a low solute concentraion.
363
What are the three main advantages of cross-pollination?
## Footnote
Increase in variation after something, why is this good, plus protection against a certain thing...
* Increase the variation in the progeny after genetic recombination.
* Increases adaptability of the offspring to environmental changes
* Give plants protection against pathogens.
364
What are platy peds?
Flat, rectangular peds :3
365
How can a plant's environment become (relatively) hypertonic?
If the plant itself cannot obtain/retain enough water.
366
What is tonicity (two ways of defining it)?
* The concentration of solute within a solvent.
* The capacity of a cell to gain or lose water.
367
What plant organ primary produces new living tissue?
The stem.
368
What's genotype fitness?
* The average fitness of all individuals in a population that have a specific genotype (e.g., the fitness of green beetles within a population of green and brown beetles).
* It can change depending on the environment.
369
Osmosis is all about probability. Why?
Less solutes = more open pores = more likely water molecules will pass through a membrane.
370
How can soil texture affect its water content?
Finer textured soils have a larger surface area and pore space, thus increasing retention.
371
Why are evergreen needles dark in colour?
So they can absorb more solar radiation.
372
What are extrusive igneous rocks? (4 Points)
* They are produced when magma exits and cools as lava at or near the Earth's surface.
* As the lava cools quickly meaning that mineral crystals don't have much time to grow.
* This results in rocks with a very **fine-grained or even glassy texture**.
* Hot gasses are often trapped in the quenched lava, forming bubbles **(vesicles)**.
373
What do birch tree catkins look like?
## Footnote
Note that female catkins are shorter, green and upright.
374
How big can a vacuole grow?
It can grow to fill up to 90% of a cell's intracellular space.
375
What are the most important pollinators in the UK?
Hoverflies! Bees get more attention because they're in decline.
376
What does the nucleus do?
## Footnote
Includes maintaining cell shape
Asides from the obvious stuff, the nucleus coordinates activities within a cell. It also maintains the cell’s shape.
377
How does nitrogen get back to the atmosphere when animals and plants die? (Quite simple)
It's released by decomposers!
378
What determines how difficult a cation is to acquire from the soil?
Its charge (e.g., Fe+3 is very difficult for plants to acquire). They're preferentially held by the soil over those with lower charges (e.g., K+ and Ca+2 go first if Fe+3 is present).
379
What's soil adhesion?
Soil adhesion is due to the negatively charged soil particles bonding with the positively charged hydrogen atoms in the water.
380
What are the four types of plant root?
* Tap root
* Fibrous root
* Aerial root
* Adventitious root (develops as the result of an external factor rather than by adherent design).
381
What's the light independent (dark) phase of photosynthesis also known as?
The Calvin-Benson cycle.
382
What helps to prevent the build-up of diseased plant tissues? What do they detect?
Regulatory molecules that are embedded in a plant cell's cell wall. They detect pathogens.
383
The cell wall stops the plant from obtaining too much...
Water!
384
What are the cytoplasmic bridges between plant cells called? What is transferred through them?
Plasmodesmata. Signalling molecules are passed through them.
385
# **
A key characteristic of evergreens is that they retain their leaves through the winter so that they can...
...photosynthesise as soon as temperatures rise again.
386
What's a surface seal? Just how porous is it?
* A surface seal or crust is a thin layer (1−10mm) formed on the soil surface by water drop impact.
* It can have a porosity 90% lower than that of an unsealed soil.
* Permeability declines during rain or irrigation when the surface aggregates break down and are compacted under drop impact.
387
Name eight different types of organic matter that can be added to soil
* Green animal manures and slurries
* Digestates (Digestate is the material remaining after the anaerobic digestion (decomposition under low oxygen conditions) of a biodegradable feedstock).
* Purpose grown crops
* Composts
* Paper crumble/wood bark
* Leaf mulch
* Seaweed
388
Why is it important to know the difference between monocots and dicots?
So you know what conditions to provide for a plant!
389
Give three places where you can find nitrogen-fixing bacteria/prokaryotes.
* The soil
* Water
* Inside of plants
390
What does it mean if conditions are isotonic?
That there's a balanced concentration of solutes between extra and intracellular environments.
391
How many layers does a plant's cell wall have?
Two (a primary and secondary layer).
392
What kind of seeds typically only have one layer of integument? (2 Reasons).
## Footnote
Angiosperm, or gymnosperm?
Gymnosperm seeds - this is because they're often dispersed by the wind. Their seeds are also protected by a nice, hard cone.
393
Name three bonus grass leaf components.
* Collar (outside of the leaf at the junction between the sheath and the blade).
* Ligules
* Auricles
394
What is a leaf's lamina?
It's the length of a leaf. It's the bit between the petiole and the apex.
395
Root tissues of monocot plants are __________, with the epidermis, cortex, endosperm, and pericycle ____________________. However, The vascular tissues of monocots form __________, with the xylem _________________.
Root tissues of monocot plants are **similar**, with the epidermis, cortex, endodermis, and pericycle **roughly the same**. However, The vascular tissues of monocots form **bundles**, with the xylem **toward the inside**.
396
What are compensation points?
* When the amount of carbohydrate manufactured in photosynthesis is equal to the amount of carbohydrate broken down in respiration.
* Sugars are converted into starch which accumulates in the chloroplasts.
* Equilibrium is avoided and more glucose can be formed.
* At night the starch is hydrolysed and distributed through the plant to growing regions and storage organs.
397
What's a soil's "wilting point"?
The point at which only hygroscopic water occurs.
398
Why does increasing wind speed increase the rate of evapotranspiration?
Moving air removes water vapour, increasing the rate of diffusion of water vapour from the leaf.
399
What organelle fills with water to exert turgor pressure? Why does it do this?
The vacuole. It does this to keep the plant stiff and to prevent it from wilting.
400
What are bilayers made of?
Phospholipids and proteins.
401
What are the three different types of grass leaf sheath?
## Footnote
S.O.U.
402
The fittest individual is not necessarily...
The strongest, fastest, or largest individual.
403
What are the three processes involved in the creation of sedimentary rock?
* Compaction: The process of consolidating fine-grained sediments.
* Cementation: The process by which clastic sediments (bits of pre-existing abiotic rock) become lithified or consolidated into hard, compact rocks, usually through deposition or precipitation of minerals in the spaces among the individual grains of the sediment.
* Lithification: The conversion of loose sediment into solid sedimentary rock. Several processes, including compaction of grains, Cementation of the layers and crystallization act to solidify the sediment.
404
What is located between the xylem and phloem with a root cylinder's vascular bundle?
Vascular cambium!
405
Do grasses normally have opposite or alternating leaves?
They have alternating leaves!
406
What's an upside and a closely related downside of using hypogeal germination?
* The cotyledons aren't dependent on light to provide the seedling with nutrients.
* However, the seedling is in a race against time to become self-sustaining as nutrient supplies are limited.
407
Phloem transports __________ and ______________ up and down the plant. This is called ____________________. In general, this happens between where these substances are made (the __________) and where they are used or stored (the _______).
Phloem transports **sugars** and **amino acids** up and down the plant. This is called **translocation**. In general, this happens between where these substances are made (the **sources**) and where they are used or stored (the **sinks**).
408
How are metamorphic rocks formed? (3 Points)
* They form when high temperatures and pressure act on a rock to alter its physical and chemical properties.
* These conditions often stretch, twist and fold the rock as it cools.
* In metamorphic rocks some or all of the minerals in the original rock are replaced, atom by atom, to form new minerals.
409
Why do anions leach so easily?
* Because most of the worlds soil particles are negatively charged (except for tropical soils that are positively charged).
* Therefore, anions cannot bind to soil particles and are washed away.
410
What's a drawback of being a female dioecious angiosperm?
You must have a male within your close proximity in order to achieve reproductive success.
411
What happens to water when it's at 3.98 degrees celcius?
When water is 3.98 degrees Celsius its density exceeds that at higher or lower temperatures. In other words, it becomes heavier than water at freezing point.
412
What's a key difference between collenchyma and sclerenchyma ground cells?
Collenchyma cells are alive at maturity - unlike sclerenchyma cells.
413
What occurs during the second stage of mitosis? (5 Points)
* The spindle fibres from the centrioles attach to the chromosomes. The spindle fibres attach at the centromeres of each chromosome.
* The chromosomes line up at the equator.
* The spindle fibres pull the chromosomes, making them line up in the centre of the cell (at the metaphase plate).
* Chromosomes are still visible as two sister chromatids joined at the centromere.
## Footnote
The metaphase
414
Why does plant cation exchange increase make the soil more acidic/lower its pH? (Three parts)
* Because plants exchange H+ ions for positively charged nutrients.
* The roots also release CO2 from respiration which combines with water, which causes H+ ions to be released upon disassociation.
* This acidification neutralises the clay particles' negative charges, meaning the roots can then absorb the nutrients that get released into the soil solution.
415
Name two genera of nitrogen-fixing bacteria that live inside root nodules.
*Rhizobium* and *Bradyrhizobium*
416
Why do habitats on the coast often have more moderate air temperatures than inland habitats?
Because the temperature of the ocean is slow to change, the air temperature near the ocean is also slow to change.
417
Why is the endosperm necessary in monocots?
Because they mainly use hypogeal germination (so the cotyledon doesn't photosnthesise, instead it extracts nutrients from the endosperm).
418
What are the three theories for how life was created
* Creationism
* Intelligent Design Theory
* Evolution Theory
419
Fill in the blanks!
420
Where does photosynthesis primarily occur within a leaf?
The vast majority of photosynthesis occurs within the palisade mesophyll.
## Footnote
Side note: a palisade is a bunch of blocks in medieval times.
421
Name the three different types of weathering.
* Physical
* Chemical
* Biological
422
What are mitochondria also known as?
Chondriosomes.
423
What's the first structure to emerge from a dicotyledonous seed?
A taproot!
424
Porous soils have a balance between...
Micro and macro pores!
425
What develops after the plumule (baby shoot)?
The radicle - this develops into roots!
426
Are deciduous trees typically anemophilous or entomophilous?
Anemophilous.
427
What do plants that live in marshes and bogs possess? Why?
* These plants produce “breathing roots” to help them with air exchange.
* This is because they have underground roots but can’t absorb gases from leaves.
428
What do female holly flowers develop into?
Red berries that are retained throughout the winter.
429
Why are xylem cells dead?
* Because they don't need to be alive.
* They die through a process called lignification. This is where the cells are strengthened through the addition of lignin. The cells then acquires strong supportive capabilities.
430
What part of this is a cotyledon? What will it do? Is this epigeal or hypogeal germination?
* The oval bit (there's another one on the other side).
* It will develop chloroplasts and photosynthesise, enabling the production of glucose.
* Since the cotyledons are above ground, this is epigeal germination.
431
Where is the root pericycle located?
It's located behind the endodermis
432
How do you do the conductivity method for measuring soil water content? What's it's main upside (and downside)?
* Use a meter recording changes in electrical conductivity between across two electrodes.
* Quick and easy to carry out in the field BUT…
* Salts within the soil will affect the conductivity and may not be suitable for soils with high salt content.
433
Why can't cations bond permanently to clay particles?
A shell of water (a hydration sphere) surrounds each cation that prevents this.
434
Soil pH affects nutrient availability. Give three examples that show how.
* Nitrogen is available for plants at a neutral pH, but is unavailable at more extreme pHs (e.g., 4 and 10).
* Potassium in unavailable at low pHs (less than 5.5.) but very available at higher/more alkaline levels.
* The more acidic soils are, the more readily available iron is.
435
What facilitates surface tension?
Hydrogen bonding.
436
What are the three main functions of the root cylinder pericycle?
1. The initiation of lateral roots
2. Contribution to the initiation of the vascular cambium
3. Initiation of the cork cambium
437
The point at which a cell will divide into two (separating the two new nuclei and cytoplasm) during mitosis is called what?
## Footnote
Not a stage of mitosis
The cleavage furrow.
438
What is a leaf vein an extension of?
A leaf vein is an extension of the xylem and phloem into the leaf.
439
What gives flowers their colour?
Chromatophores (very basic ones).
440
Give two pros of using organic compounds
* They're readily available
* There isn't so much environmental damage from their production
441
What is infiltration capacity?
* It includes surface infiltration and percolation.
* It's expressed in depth of water per unit of time, usually inches per hour or centimetres per hour.
442
What are perlite and vermiculite?
Hydroponic growth mediums
* Perlite is a substance made from volcanic rock.
* It's white, light weight and often used as a soil additive to increase aeration and draining of the soil.
* Vermiculite, which is used the same way as perlite and often mixed together, is made from heat expanded mica and has a flaky, shiny appearance.
443
Give six common irrigation schedules.
## Footnote
Intervals, neighbours, visual stress, measuring, budget, combo.
1. Irrigating on fixed intervals or following a simple calendar, i.e., when a water turn occurs or according to a predetermined schedule;
2. Irrigating when one's neighbour irrigates;
3. Observation of visual plant stress indicators;
4. Measuring (or estimating) soil water by use of instruments or sampling techniques such as feel, gravimetric, electrical resistance (gypsum) blocks, tensiometers or neutron probes;
5. By following a soil water budget based on weather data and/or pan evaporation; and
6. Some combination of the above.
444
What are rhizomes?
They're modified grass stems that run underground. New roots and a plant grow at each node.
445
What's mineralization?
The process by which bacteria break down organic matter into ammonium (NH4+).
446
What does "50% relative humidity" mean?
50% relative humidity indicates the air is carrying one-half of the maximum amount of moisture that it can contain at the given temperature.
447
When pollen is spread by the wind, this is called...
Anemophily!
448
If a seed is dispersed through epizoochory, what will it usually possess?
Little hooks.
449
What are wheats and barleys known as (genus names)?
*Triticum* and *Hordeum* respectively.
450
What does CEC stand for?
Cation Exchange Capacity
451
What two mitosis stage-thingies occur side-by-side? When does the former also occur?
* Cytokinesis essentially happens alongside the telophase.
* Cytokinesis is the physical process of cell division - the cytoplasm of the parent cell is divided into two daughter cells.
* It also occurs during meiosis as well as mitosis.
452
Is the plasma membrane on the inside or the outside of the cell wall?
It's on the inside of the cell wall.
453
Within a water molecule, the two hydrogen atoms are bound to the oxygen atom at an angle of...
## Footnote
The larger number
104.5 degrees!
454
What's an endosperm?
A nutritional sac that's found only in monocot seeds/embryos.
455
* What are the two main roles of a waxy cuticle?
* Where is it located?
* The main function of thew waxy cuticle is to prevent water loss. It also stops waterborne diseases from getting in.
* It covers both the upper epidermis and the lower epidermis.
456
Name three different types of large particle medium used in hydroponics
* Sand
* gravel
* Expanded clay pellets
457
What's a biennial?
A plant that completes its life cycle in two years, typically flowering and fruiting in the second year.
458
Guard cells don't contain chloroplasts. True or false?
False - they do contain chloroplasts.
459
What are the three main types of plant storage organ? What are they modifications of?
* Bulbs (modified leaf bases)
* Storage roots (modified tap roots)
* Tubers (modified stems)
460
What's notable about grass seeds when they mature?
They're dormant!
461
What happens to female conifer flowers once they become pollinated?
Once pollinated by wind, female flowers turn green and enlarge to become red-brown cones with diamond-shaped, rounded scales.
462
The phenotype is simply...
The observable, physical properties of an organism - the physical expression of the genotype.
463
What are the three parts of a vacuole that you need to know?
464
What's the topsoil/A horizon? Do plants like it?
* Mostly minerals from parent material with organic matter incorporated.
* A good material for plants and other organisms to live.
465
Name all 6 of the ways water can change state.
## Footnote
FM, VC, DS
466
All monocots use _______________ germination.
Hypogeal/below ground germination.
467
What are batholiths? Give an example of one.
* Batholiths are large, deep-seated intrusions (sometimes called Plutons) that form as thick, viscous magma slowly makes its way toward the surface, but seldom gets there!
* Dartmoor forms part of a large batholith that extends under Cornwall and beyond.
468
Where does most SOM originate from?
Plant tissue.
469
Give three examples of monoecious angiosperms.
* Cucumbers
* Coconuts
* Squashes
470
What are the two main roles of cytoplasm?
* To be a suspension medium for organelles.
* To maintain the shape of a cell.
471
What's notable about the calyx and corolla of dicot flowers? (3 Points)
* Most of the time, the two appear to be very separated from each other.
* Some monocots have their sepals and petals conjoined.
* If a bud looks as though it's made if petals, then it's likely a monocot.
472
What plant cells contain high numbers of mitochondria?
## Footnote
Not root hair cells!
Phloem companion cells (because they need to sieve stuff and transport things).
473
What's found above and below a cotyledon?
The epicotyl and the hypocotyl respectively!
474
Give several things that can influence the rate of transpiration.
* It's largely controlled by the **humidity of the atmosphere** and the **moisture content of the soil**.
* Vegetation type
* Canopy density
* Coverage of plants.
* Types and depth of roots.
* How much water moves into and out of leaves.
* The light reflected off the plant.
475
Are grasses monocots or dicots?
They're monocots!
476
What is contained within a carpel's style?
The transmitting tract **extracellular (outside cell) polysaccharide matrix** that pollen tubes stretch down.
477
How are dykes formed? What are exactly are they?
Dykes form as magma pushes up towards the surface through cracks in the rock. Dykes are vertical or steeply-dipping sheets of igneous rock.
478
* What do adventitious roots grow from?
* Why?
* Give an example of a plant with adventitious roots.
* Adventitious roots grow from non-root tissue.
* They are produced during normal development and in normal response to stress conditions such as flooding, nutrient deprivation and wounding.
* Strawberries naturally have adventitious roots (they’ll grow stems that grow into the ground to create new plants).
479
What's the male reproductive organ of a flower called? What are its two main components?
The stamen
* The anther (bit that produces pollen)
* The filament (extends the anther upwards so its pollen can be dispersed)
480
What are the qualities of perlite and vermiculite?
* Perlite has good wicking action, but doesn't retain water very well, which means it will dry out quickly between waterings.
* The opposite is true of vermiculite; it retains too much water and can suffocate the plant's roots if used straight.
481
Give two ways of decreasing soil pH
## Footnote
The addition of a compound and the addition of an element.
* Addition of aluminium sulfate
* Addition of sulphur
482
Are spruces dioecious or monoecious?
Monoecious! (Male and female flowers on the same individual).
483
How are hydrogen and oxygen atoms bonded within a water molecule?
Through covalent bonds.
484
How are stomata opened up?
Water enters the vacuoles in guard cells.
485
Where is sphagnum moss best used as a hydroponic medium? What's its main downside?
## Footnote
Moss can hold large quantities of two things, what sort of container should it be stored in, what can become clogged up?
* Sphagnum moss has long strands of highly absorbent, spongelike material that hold and retain large amounts of water while simultaneously having good aeration.
* Because of this structure, it is best used in larger lattice or net-pot production where the long strands can spill out the holes in the pots to wick up water without falling out.
* Can decompose over time and shed small particles that can plug up your pump or drip emitters.
486
What's creationism?
* All life was created by God
* Genesis is a historical recount of events (e.g., Adam and Eve, Noah's Flood).
* Earth is only 6,000-10,000 years old (not 4 billion).
487
Spongy mesophyll cells are adapted...
Parenchyma ground cells!
488
Flowering plants can be divided into three categories. What are they?
* Dioecious angiosperms (males and females)
* Monoecious angiospems (male and female flowers on one individual)
* Hermaphrodites (male and female organs within the same flower)
489
Describe pulverised bark as a hydroponic growth medium.
## Footnote
Where does it come from, how does it hold stuff, is it cheap, is it inert, and what's its pH?
* Normally Coniferous bark.
* Fibrous structure holds the nutrient solution and air for long time.
* Cheap and readily available.
* Needs to be rendered inert; fresh pine bark will absorb nitrogen from the nutrient solution.
* The pH of pine bark is acidic; it ranges between 4.0 and 6.5 even when aged.
490
What are the four different types of soil fertilisation?
* Organic
* Inorganic
* Compound
* Controlled release
491
What are the four layers of the root vascular cylinder? (Within which xylem and phloem can be found)
* Epidermis
* Cortex
* Endodermis
* Pericycle
492
What is the outer layer of a seed called (not the seed coat/testa)?
The integument (the seed coat and testa develop from this).
493
What is aeration? What does it promote the growth of?
The process of introducing air into the soil to promote the growth of **healthy plant roots**.
494
Do plant roots cause soils to become more acidic over time?
Yes, the release of H+ ions in exchange for cations from clay particles does acidify soils over time.
495
What does the SER do? (2.5 Points)
* It produces lipids and manufactures new membranes.
* It also metabolizes carbohydrates.
496
* Root hairs are the most common type of what?
* What's their purpose?
* How long do they live for?
* What do they never develop into?
* The most common type of trichome.
* Greatly increase the surface area of the root, Improving the absorption of water and minerals.
* Root hairs live for only a few days and never develop into multi-cell roots.
497
What's a pro and con of entomophilous pollination?
* Pro: more targeted
* Con: if insects disappear then plants can't reproduce
498
The cell walls between phloem cells get small ________ to allow __________ to pass through. This is called a ____________________.
The cell walls between phloem cells get small **holes** to allow **sugar** to pass through. This is called a **sieve tube plate**.
499
What is the opposite of an autotroph (an ORGANISM that makes its own food by taking carbon from CO2).
A heterotroph - something that takes carbon from those it consumes...
500
What's the difference between single grain and structureless peds?
## Footnote
Note: may not be referring to peds, may be soil structures.
Single grain: no aggregation of course particles when dry.
Structureless: no aggregation of fine particles when dry.
501
What determines how likely peds are to form in soils?
The amount of organic matter
* Soils with lots of organic matter are likely to form strong peds
* But soils that are sandy or have little organic matter often have little or no ped development.
502
What's an easy way to identify a wind pollinated/anemophilous plant?
Feathery stigmas to catch pollen! The stigmas of insect-pollinated plants are small, round, and sticky.
503
Why does a high humidity decrease the rate of transpiration?
Humidity decreases the concentration gradient between the inside and outside of the leaf – this reduces transpiration.
504
What are taproots characteristic of?
Dicotyledonous plants (dicots).
505
Why is the over-application of fertiliser bad? (Three generic-ish reasons)
## Footnote
It h... next is counter-intuative, last it p...
* It hardens the soil
* It reduces fertility
* It pollutes the air, water, and soil
506
What are bulbs made of?
Layers called scales (onions are a good example).
507
What is the outermost membrane of a chloroplast called?
The outer membrane :3
508
Multiple soil horizons form a...
Soil profile!
509
What features enable grasses to resist heavy grazing?
* Their extensive root systems! (It's very difficult for grasses to be pulled out).
* They grow from near their bases, not from their tips, thus they are not permanently damaged from grazing animals (or fire).
510
What are sclerenchyma ground cells? Give an example of tissue made of sclerenchyma cells.
* Sclerenchyma are woody cells.
* They have undergone lignification (and therefore they contain lignin!).
* This also means that they're dead.
* They restrict the ability of cells to elongate and grow.
* Cherry stones are sclerenchyma.
511
Each soil horizon only exhibits only one...
Soil horizon.
512
What are the two main ways in which soil aeration can be improved?
* Manually (by spiking the soil or by using a plug aerator)
* Naturally (by adding mulch to encourage decomposers and soil organisms)
513
Phospholipids have ____________ heads and ____________ tails.
Hydrophilic heads and hydrophobic tails.
514
Give three ways in which carbon re-enters the atmosphere.
* Cellular respiration
* Release during decomposition
* Burning of fossil fuels
515
Why is it best for plants to store things underground?
It’s best for plants to store things underground as they’re safe from temperatures and predators.
516
What allows things to float on water?
The surface tension of water.
517
Give the evolutionary timescale (6 Points)
* Big Bang 13 billion years ago
* Universe formed 10 billion years ago
* Earth formed 4 billion years ago
* Life formed 3.8 billion years ago
* Dinosaurs 200 million years ago
* Humans 2 million years ago
518
What are bryophytes?
Non-vascular plants (plants without xylem and phloem), such as mosses and liverworts.
519
What are two features you can use to identify an entomophilous plant?
* Bright and colourful (look for bee lines that act as runways!)
* The presence of nectaries
520
What are the products of photosynthesis?
* Glucose
* Water
* Oxygen
521
What are chlorenchma?
* A type of parenchyma ground cell.
* They're photosynthetic cells.
* Therefore, they contain high levels of chloroplasts.
522
What are the two different types of composted/aged material that are used in hydroponic basins?
* Pulversied bark
* Coconut coir
523
When a plant cell loses water and turgid pressure, what is said to occur?
Plasmolysis!
524
What are the two ions that are carried by NADPH?
Phosphorous and hydrogen ions.
525
What are catkins?
Flowers that hang in the air. Makes it nice and easy to release and capture pollen.
526
What happens when a pigment absorbs a light wave?
The wave gets passed on to the central chlorophyll molecule.
527
What are intrusive igneous rocks also known as? How are they formed?
Plutonic rocks!
* Forms when magma remains inside the Earth's crust where it **cools and solidifies in chambers within pre-existing rock.**
* The magma cools very slowly over many thousands or millions of years until it solidifies.
* This slow cooling means the **individual mineral grains have a very long time to grow, forming a rock with large, visible crystals**.
528
What are expanded clay pellets that are used in hydroponics also known as?
Grow rocks!
529
What is the main contributor of seed germination success? What is this in turn determined by?
* The quality of the messenger RNAs stored during embryo maturation on the mother plant.
* The health of the parent plant determines the quality of the mRNA within embryo.
530
What's intelligent design theory?
* It's typically not religious
* Wherever complex design exists, there must have been a designer
* Related to Aristotle
531
Soil horizons O, A, E, and B are known as...
The regolith.
532
What develops between the cotyledons in an embryo? What does this develop into?
The plumule. This develops into a shoot.
533
What are the two leaf arrangement patterns?
Simple and compound.
534
What do plants use magnesium for? (Quite simple)
Magnesium is the key element in chlorophyll.
535
Label the leaf!
1. Vein
2. Leaf base
3. Lamina
4. Venule
5. Margin
6. Midrib
7. Peiole
8. Apex
536
How do animals acquire usable nitrogen?
By eating plants or other organisms!
537
What do nutrients attach to in a soil? Why?
* Clay particles! They attach because they have positive charges (They're cations e.g., Ca+2, Mg+2, K+2 and NH4+).
* Most clay particles have a negative charge.
* Without clay, ions leach out of the soil by being carried away by water.
538
Grass leaves are narrow. What benefit does this provide?
Grass leaves lose less water than broad leaves.
539
What's the main determining factor of crop yield?
Water! Followed by nutrient availability!
540
Name three primary macronutrients for plants (all obtained from the soil)
* Nitrogen
* Phosphorus
* Potassium
541
Why is heat energy released when condensation occurs?
Since **water vapor has a higher energy level than that of liquid water (because it's a gas)**, when condensation occurs, the excess energy in the form of heat energy is released.
542
How many membranes are chloroplasts made of? What's the innermost membrane called?
Three. The innermost layer is called the thylakoid.
543
An organism that consumes other organisms is called...
A heterotroph!
544
What's notable about the phosphorous cycle?
The phosphorus cycle is slow compared to other biogeochemical cycles such as the water, carbon, and nitrogen cycles.
545
What are the four different types of adventitious roots?
(Note that etiolation is where plants are grown without light. The roots grow when the plant is exposed to light).
546
Why does ice float?
When water freezes, it forms a crystalline structure where each hydrogen atoms bonds to four other water molecules. This causes water/ice to expand/become less dense.
547
Give three cons of controlled release fertilisers
* Unable to customise balance of nutrients
* The rate of application cannot be varied
* They're expensive
548
What percentage of flowering plants are dioecious angiosperms?
Six percent.
549
What are the four main benefits of oasis cubes?
* Hold over 40 times their weight in water.
* They have wicking action that draws water to the top of the foam.
* They have a neutral pH.
* They can be easily transplanted into practically any kind of hydroponic system or growing medium.
550
Where will you find aerial roots? Why?
## Footnote
What biome?
In rainforests (because their soils are so poorly oxygenated).
551
What are other words for "above ground" and "below ground" germination.
Epigeal and hypogeal.
552
* What's the bedrock/R horizon?
* What's it made of (five possible materials).
* Is it really soil?
* A mass of rock such as granite, basalt, quartzite, limestone or sandstone that forms the parent material for some soils – if the bedrock is close enough to the surface to weather.
* This is not soil and is located under the C horizon.
553
Water has the highest known surface tension of any known liquid. True or false?
True!
554
What triggers the growth of a pollen tube?
Carbohydrates on a stigma.
555
What five things do plants NEED in soil?
* Nutrients (Phosphorous, Potassium and Nitrogen).
* Air.
* Water.
* Correct pH.
* Organic Matter.
556
What are auricles?
Small appendages at the junctions between grass blades and sheaths.
557
Grass leaf ligules come in three different varieties. What are they?
* Hairy
* Absent
* and membrane-like
558
Give three pros of controlled release fertilisers
* Control of nutrient release
* Only needs to be applied once
* Reduced risk of leaching
559
What is the first step in the creation of soil?
Weathering!
560
What are the three phases in a cell's life cycle? What are all three grouped under?
* Growth 1 (G1)
* Growth 2 (G2)
* DNA Synthesis (S).
Interphase includes all three of them.
561
What are yew flowers like?
* Male flowers are insignificant white-yellow globe-like structures.
* Female flowers are bud-like and scaly.
562
Do clay-based soils or sandy soils hold more water?
Clay-based soils (remember that clay particles are smaller than sand particles).
563
What is a palea? What about a lemma?
* The palea is the inner bract of a grass floret
* The lemma is the outer bract of a grass floret
## Footnote
This is correct
564
What are the two primary requirements of the light independent (dark) phase of photosynthesis?
* Carbon dioxide
* Warmth
565
How large are clay soil particles/serparates?
They're less than 0.002mm.
## Footnote
The smallest particles.
566
What's the difference between a centriole and a centrosome?
A centriole is a barrel-shaped organelle which lives normally within the centrosome. The mitotic spindle is formed from centrioles during the prophase phase of mitosis.
567
What do auricles look like on a real piece of grass?
568
Which of the three plant macronutrients is often limiting: nitrogen, phosphorus, or potassium?
Phosphorus!
569
The many ____________________ in the root hair cell provide the energy required for ____________________ of ____________________.
The many **mitochondria** in the root hair cell provide the energy required for **active transport** of **scarce minerals**.
570
What's a ped? How are they held together?
A ped is an aggregate of soil particles. They're held together by electrical charges on the surfaces of minerals and organic matter.
571
Over-application of fertilisers can cause what part of a plant to become underdeveloped?
Root systems - they become inefficient because of sudden plant growth.
572
* What's created by high axle loads under moist soil conditions?
* What does this prevent when soils eventually dry out?
## Footnote
SSC!
* Subsurface compaction!
* When the soil dries, it prevents roots from accessing deep stored moisture.
573
What are angiosperms that have male and female flowers on different individuals?
Dioecious angiosperms!
574
How is the xylem arranged in a vascular bundle?
In an X shape. Phloem is located between the arms of the X.
575
Cotyledons are NOT...
True leaves. This is because they're a part of the embryo. Regardless, they serve the same purpose as leaves.
576
What helps to bind soil into aggregates?
Organic matter!
577
Why is precipitation always freshwater, even if the water came from the ocean?
Because salt does not evaporate.
## Footnote
Remember that pollutants can still enter rain droplets.
578
How exactly do pollen tubes extend down a style?
The tubes possess digestive enzymes that digest their way down the style's polysaccharide matrix.
579
What's the peduncle on a flower (and pedicels?)
* A short flower stalk in an inflorescence or cluster of flowers.
* Hold individual flowers in place and exposes them to the sun and wind and put them in a position so their aroma and colour attracts pollinating insects more easily.
* Groups of pedicels form an inflorescence branched from the peduncle (Main stem).
580
What two things happen to a flower when its ovules are fertilized?
* The petals drop off
* The ovary develops into a fruit
581
What are controlled release fertilisers?
## Footnote
Hint: they're particles that a coated with something for a certain reason.
Granular fertilizer particles that are coated with a polymer or resin that restricts the amount of moisture contact and functions to dissolve the fertilizer particles to gradually release fertilizer over time.
582
Give four things that increase soil pH/make it more alkaline
| FULUn
* Fertilisers
* Urine
* Leaching
* Unused nitrates
583
What's the root cap? What does it secrete?
* The root cap protects the delicate apical meristem as the root pushes through rough soil.
* Secretes a viscous mucilage/gelatinous substance that helps the root to penetrate the soil.
584
How do hardsetting layers form? How are they made even worse (two ways)?
* Soil aggregates break down during wetting, then set to a hard, structureless mass during drying.
* This can be exacerbated by over-cultivation and reduction in organic matter, which reduces aggregate stability.
585
What colour are yew leaves? How are the leaflets arranged?
* The leaves are dark green on top, and greyish-green on the bottom.
* The leaflets alternate along their tiny stem.
586
What's the subsoil/B horizon?
Rich in minerals that leached (moved down) from the A or E horizons and accumulated here.
587
How do rainwater droplets change shape as they grow? Why does this happen?
* Small raindrops (radius < 1 millimeter (mm)) are spherical; larger ones assume a shape more like that of a hamburger bun.
* When they get larger than a radius of about 4.5 mm they rapidly become distorted into a shape rather like a parachute with a tube of water around the base --- **and then they break up into smaller drops**.
* This evolution results from a tug-of-war between two forces: the **surface tension** of the water and the **pressure of the air pushing up against the bottom of the drop** as it falls. **When the drop is small, surface tension wins and pulls the drop into a spherical shape**. With increasing size, **the fall velocity increases and the pressure on the bottom increases, changing the droplet's shape**.
588
Why are ash leaves special?
The leaves can move in the direction of sunlight, and sometimes the whole crown of the tree may lean in the direction of the sun.
589
What's rockwool? Where would you use it? What's its main benefit?
* A hydroponic growth medium made from rock that has been melted and spun into fibrous cubes and growing slab.
* Can be used with continuous drip or ebb and flow systems and is suitable for plants of all sizes, from seeds and cuttings to large plants.
590
What are the 5 specialized plant cells that you should know?
* Palisade cells
* Spongy mesophyll cells
* Guard cells (these surround stomata)
* Xylem cells
* Phloem cells
591
What is the process by which plants shed their leaves, flowers, and/or fruits?
Abscission
592
What's the accumulation of leached materials from an overlying stratum called?
Eluviation.
593
Does increasing the amount of CO2 increase the rate of photosynthesis?
Yes, it does.
594
A leaf has...
* A leathery feel to it.
* Its leaves are also turning purple...
What element is required?
Phosphorus!
595
Water is capable of dissolving...
...More substances than any other liquid.
## Footnote
It has high solvent power.
596
What is a plant's cell wall made of?
Cellulose
597
What is the perianth?
The calyx and the corolla combined!
598
Cones help to protect seeds from _________ temperatures.
Cold temperatures!
599
What are the three main methods of seed dispersal?
* Autochory (self-dispersal)
* Anemochory (wind)
* Zoochory (animal)
600
What's the size range for expanded clay pellets?
1-18mm.
601
Which leaf is a monocot leaf? Which one is a dicot leaf?
* Left: Monocot.
* RIght: Dicot.
602
Why is fitness a handy concept?
It lumps everything that matters to natural selection (survival, mate-finding, reproduction) into one idea.
603
Give two things within a soil that can influence its pH
* Parent material
* The amount of organic matter
604
What is a seedling entirely dependent on?
Its cotyledon(s) - they provide nutrients through photosynthesis or through the endosperm.
605
What do cross-sections of dicot and monocot stems look like?
Don't get these mixed up!
606
What happens to this bell curve during the winter?
It becomes more constricted due to less light.
607
Where does the light independent (dark) phase of photosynthesis take place?
Within the stroma (the cytoplasm of the chloroplast).
608
Give three pros of using inorganic fertilisers
* Much greater control over nutrient levels
* They act very quickly
* They're cheaper than organic fertilisers
609
How do holly leaves change as they get older?
Young leaves on the lower branches are spikey but become smoother and more oval as they age and move upwards as the plant grows.
## Footnote
Remember that, like all evergreens, holly leaves are waxy.
610
Give three things that can trigger a hormonal response that will end dormancy within a seed.
* The sudden appearance of light.
* Being defecated by an animal.
* Wildfires (the fire will melt the testa slightly, ending dormancy).
611
Give a great example of convergent evolution.
* Sharks, dolphins and penguins!
* One's a fish, one's a mammal, and the other's a bird.
* Yet they all have similar body shapes (in water they're streamlined) because of similar selection pressures!
612
What are spongy mesophyll cells covered in?
A thin layer of water. Gases dissolve in this water as they move into and out of the cells.
613
What does the waxy coating do on evergreen leaves?
It helps to prevent evapotranspiration.
614
What's seed vigour? What's it driven by?
Seed vigour is the speed of germination. It's "driven by the ability of a plant embryo to resume its metabolic activity in a coordinated and sequential manner."
615
What conditions are required for evaporation to occur?
## Footnote
Water has to be in contact with something, and it has to be a certain temperature...
* Water is in contact with the atmosphere
* The temperature is above 4 degrees Celcius
616
* What's air/gravitational soil in water?
* What causes it to drain?
* At what level does it occur?
* Water that percolates through or fills the macropores (gaps between particles) of soil at saturation.
* Drains under the influence of gravity.
* Occurs at the water table level.
617
Why is the cell cycle a cycle and not a linear pathway?
Because at the end of each go-round, the two daughter cells can start the exact same process.
618
What do spruce leaves look like?
## Footnote
Dark green, waxy, and spiked!
619
What's a sill? Give an example.
* Sills form when magma intrudes between the rock layers, forming a horizontal or gently-dipping sheet of igneous rock.
* The Whin Sill in N. England provided a defensive cliff-line on which the Romans built Hadrian’s Wall.
620
What is xylem?
Plant **tissue** that transports **water and nutrients** ***up*** from roots to stems and leaves.
621
What is an autotroph?
An organism that can produce its own food by using carbon dioxide.
622
Remember that there are only two...
Sperm nuclei that travel down a pollen tube!
623
When will water vapor begin to condense around condensation nuclei (e.g., pollen and dust).
When air reaches the saturation point or Dew point temperature.
624
What are the symptoms of nitrogen deficiency? (Two things)
* Plant appears pale/yellow - decreased production of chlorophyll.
* Plant growth slows, will become stunted.
625
# ****
What's the main disadvantage of ebb and flow hydroponics?
The main disadvantage of this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), there is a **vulnerability to power outages as well as pump and timer failures**. **The roots can dry out quickly when the watering cycles are interrupted.**
626
What is cytoplasm made of?
Water, salts, and proteins.
627
What is a soil's pH primarily determined by?
The kinds of parent material from which the soil was formed.
628
Can plants respire anaerobically?
Yes - but they produce ethanol instead of lactic acid (just like yeast).
629
Fertilisers can undergo nitrification. What does this mean and why is it bad?
* Ammonium gets converted into nitrate by bacteria.
* This causes hydrogen ions (H+) to be released, which raises the acidity of the soil.
630
Is there only one type of vacuole?
* No. Some plant cells contain vacuoles that contain enzymes that breakdown macromolecules.
* Some also store cellular nutrients, such as sugars, salts, proteins, pigments, and lipids.
631
Give two examples of anions
* Nitrate
* Sulphate
632
What happens to starch at night?
It's hydrolysed and distributed through the plant to growing regions and storage organs.
633
How are chemical sedimentary rocks formed?
* Chemical sedimentary rocks form by chemical precipitation that begins when water travels through rock and dissolves some of the minerals and transports them away. Chemical sedimentary rocks form from these minerals.
* Eventually dissolved minerals are redeposited, when the water evaporates or when the solution becomes over-saturated with minerals.
634
What are organic compounds usually derived from?
* Crop residues
* Animal manures
* Slurries
635
How large are sand soil particles/separates?
Between 0.05 to 2mm.
## Footnote
The largest particles.
636
What does an entire ovary develop into once it's fertilized?
A fruit.
637
What percentage of water do plants "use"?
4-5%. The rest is used to get water and nutrients to where they need to be.
638
What does the thickness of a seed coat/testa depend on?
The seed's method of transportation.
* For example, if it's dispersed by an animal's insides, then the coat will be thick to withstand acid.
* If the seed is dispersed by the wind, then it'll be light.
639
What enables warm blooded organisms to more evenly disperse heat in their bodies?
The high heat capacity of water.
640
What is "soil structure"?
Soil structure is the arrangement of soil particles into small clumps, called peds.
641
Is pollen itself a gamete?
No - but it transports them!
642
How do legumes acquire nitrogen-fixing bacteria?
## Footnote
Legumes release something, and then bacteria attach to something, then they activate something...
* The process begins when the *rhizobia* are attracted to **flavonoids** released by the host legume’s roots.
* The bacteria then begin to attach themselves to extensions of **root epidermal cells** called root hairs.
* The bacteria trigger the plant to activate genes that cause the root hairs to curl, allowing the bacteria to penetrate the root and form nodules.
643
What's the purpose of a pedicel?
## Footnote
It increases the exposure of something to another thing...
To make the pollen more exposed (e.g., more easily obtained by insects and the wind). (provides the correct orientation of the flower to facilitate pollination).
644
What's the humus/O horizon? Is it present in all soils?
* Mostly organic matter such as decomposing leaves.
* The O horizon is thin in some soils, thick in others, and not present at all in others.
645
Fill in the blanks!
646
What's humus?
The stable organic fraction of soil that absorbs and holds nutrients in a plant-available form.
647
Where do proteins made within the RER get sent to?
Proteins made within the RER get sent to the golgi apparatus. From there, they’re sent to other parts of the plant.
648
What are the three main disadvantages of cross-pollination?
* Requires agent of pollination – insect or bird / wind.
* Require plant to produce structures to attract pollinators
* Not suitable where numbers of flowers are small or widely spaced.
649
Grass leaves are made of two components. What are they?
* The leaf blade (lamina).
* The sheath (tubular, lower part of the leaf that encloses the stem. It protects younger shoots and provides support).
650
What is phloem?
Plant **tissue** that transports **food** ***down*** from leaves to roots.
651
What determines the point at which condensation occurs?
"It's not a matter of one particular temperature but of a difference between two temperatures; the air temperature and the dewpoint temperature."
## Footnote
In other words, the point at which condensation occurs is not a very specific temperature.
652
What are the three soil particle types?
* Sand
* Silt
* Clay
653
Deciduous trees generally flower when they are ______less.
Leafless (in order to increase the chances of pollination).
654
What are ground cells? What are the three main types of ground cell?
* Ground cells make up the vast majority of a plant's structure.
* Parenchyma
* Collenchyma
* Sclerenchyma
655
When is glucose created? What is it made of?
It is created during the Calvin-Benson cycle. ATP and NADPH produce glucose by using carbon from CO2 (through the addition of ions).
656
What are the secondary functions of xylem?
* Mechanical support
* Storage
657
How are hills and mountains responsible for "relief rainfall".
## Footnote
You'll need to include how much warm air cools every 1000ft.
* Relief rainfall is where moist air is forced to rise over a physical barrier such as a mountain range.
* As it rises, the warm air cools with height at a rate of 3°C per 1000ft (the DALR rate).
* As the air cools water vapour condenses to form clouds and eventually rain.
658
How is the "raceme" spikelet inflorescence arrangement defined?
"Spikelets are stalked on pedicels directly from the primary axis."
## Footnote
This formation is quite rare.
659
Give four different ways that seeds can modify themselves to achieve anemochory.
* By being lightweight
* By developing wings
* By inflating!
* By growing hairs
660
What two components make up a grass floret?
## Footnote
Many florets make up a spikelet.
A palea and a lemma.
661
What are stomata connected to?
Vascular plant tissues!
662
Grasses can grow in three different formations. Name them?
* Caespitose (growing in dense clumps)
* Rhizomatous ("sod/turf forming").
* Stoloniferous (also sod/turf forming).
663
What's the difference between hydroponics and hydroculture?
Hydroculture is simply hydroponics including the use of a growing medium (other than soil).
664
Spikelets can be arranged in three different patterns. What are they?
## Footnote
Spikelets collectively make up a grass inflorescence.
* Raceme
* Panicle
* Spike
665
What does nitrogen exist in the atmosphere as?
N2.
666
What growth related things do plants use phosphorous for? (3 Things)
* Root formation
* Stem growth
* Fruiting
## Footnote
Don't forget that it's a key part of nucleic acids, like DNA and of the phospholipids that form our cell membranes.
667
What's irrigation?
The delivery of water to crops by man made means rather than relying upon rainfall alone.
668
What's biological weathering?
The process by which living organisms, such as plants and microbes, break down rocks and minerals, contributing to soil formation.
669
Male and female dioecious angiosperms produce fruits. True or false?
False - only females produce seed-containing fruits.
670
What's a sepal collectively known as?
The calyx (The calyx is the outermost part of a flower, made up of leaf-like structures called sepals).
671
Describe the distributions of igneous, sedimentary, and metamorphic rocks in the UK.
* Igneous: found mainly in upland areas in Scotland, in the Lake District in North West England and Snowdonia in North Wales and Northern Ireland.
* Sedimentary: widely found across lowland areas of England.
* Metamorphic: found in Northern Ireland and Scotland.
672
A plant is looking a bit yellow and it's not growing very well. What element is required?
Nitrogen!
673
What property of water enables organisms to regulate their own internal temperatures?
Water's high heat capacity (it maintains temperature more successfully than most other substances).
## Footnote
Remember that most organisms are mostly made of water.
674
Give six things that can cause nutritional deficiencies
* Acidic or alkaline soil (affects nutrient availability)
* Deviation from optimum pH
* Soil Type
* Leaching
* Drought
* Waterlogging
675
What are collenchyna ground cells?
* They are thick, yet pliable
* Leaf petioles are made of collenchyma cells
* They provide structural support without restricting growth
* Cells are stacked end on end and are oriented in strands just beneath the epidermis
676
What is the second main structural organ of a vascular plant?
The stem (the root is the primary structural organ).
677
What influences the rate of osmosis?
The difference in tonicity between two fluids (if the difference is high, then the rate of osmosis will be fast).
678
Where within a chloroplast can you find chlorophyll?
Within the thylakoid membranes/granums.
679
What four qualities must a hydroponic growing medium posssess?
* It must be inert (Inert mediums are chemically neutral and do not provide any nutritional value to the plants. They primarily function as a support system for the roots while allowing the free flow of water and nutrients).
* It needs to have a porous structure
* It needs to be penetrable by the roots
* Ideally, it should also have a close to neutral pH
## Footnote
How the medium you choose behaves with changes of temperature is also important
680
Imagine two diagrams that show monocot and dicot root tissues.
681
When will a water droplet begin to fall towards Earth?
## Footnote
When one thing exceeds another.
When the fall velocity exceeds the cloud updraft speed.
682
If six percent of all flowering plants are dioecious angiosperms, and four percent are monoecious angiosperms, then what are the remaining 90%? What are they known as?
Hermaphrodite angiosperms
* Both male and female organs are found within a single flower
* They are known as "perfect flowers"
683
The process through which seeds are dispersed explosively through ballochory is called...
Explosive dehiscence!
684
Name four biological molecules that contain carbon.
* Glucose
* ATP
* Amino acids
* DNA
685
What do guard cells help to control within a plant?
Rates of photosynthesis and transpiration.
## Footnote
Photosynthesis is controlled by limiting the amount of CO2 that can enter a plant.
686
What are the three main benefits of taproots?
* They can penetrate deep into the ground and get more water.
* They provide stability for top heavy plants.
* They're also great for storage.
687
What are the two different types of photosynthesis?
Light dependent and light independent (dark) photosynthesis.
688
Name the two different types of igneous rock.
Extrusive and intrusive.
689
What exactly is a monocotyledonous plant? What about a dicotyledonous plant? What percentage of plants are monocots and dicots?
* A cotyledon is often known as an embryonic leaf (or "seed leaves"). They are **not** true leaves.
* Monocots have one cotyledon. Dicots have two.
* **All** living plants can be divided into one or the other.
690
Give an example of a group of plants with fibrous root systems.
Grasses!
691
What do cotyledons do during hypogeal/below ground germination?
* They remain beneath the soil
* They **don't turn green and photosynthesise**
* Instead, energy comes from the endosperm
692
What do phloem vessels possess (that xylem vessels don't have?)
Unlike xylem, phloem vessels contain cytoplasm, and this goes through holes from one cell to the next.
693
Broadly, what are nitrogen, phosphorus, and potassium used by plants for?
* Nitrogen: leafy green vegetative growth
* Phosphorus: root formation, stem growth, and fruiting
* Potassium: flowering and fruit ripening, plant immunity/disease resistance, water regulation
694
What is the formula for respiration?
C6H12O6 (Glucose) + 6O2 → 6CO2 + 6H2O
695
What does CEC stand for?
Cation Exchange Capacity
696
What are the two different types of speciation?
* Sympatric - the evolution of a new species while it continues to inhabit the same geographic region as its ancestral species. (Think S for Same area).
* Allopatric - when populations get split and develop into new species. The two populations cannot breed with each other.
697
What are the three main disadvantages of self-pollination?
* Lack of variation so no adaptation to the changing environment / pathogens
* Can lead to inbreeding depression, or the reduced health of the species.
* Genetic defects in self-pollinating plants cannot be eliminated.
698
What are the three different soil particle types really called?
## Footnote
Sand, silt, and clay
Soil separates!
699
If a holly is dioecious (male and female flowers found on different individuals) then how will it likely be pollinated?
Through insect pollination.
700
What hydroponic system do expanded clay pellets work best with? Why?
Ebb and flow systems (because of the frequent waterings). This is because clay pellets don't hold much water - salt accumulation and drying out are common problems in improperly managed systems.
701
When pollen is spread by insects, this is called...
Entomophily!
702
What sort of veins do monocots have? What about dicots?
* Monocots: parallel veins
* Dicots: net-like veins
703
What's bulk density? What three things does it influence?
Bulk density is the mass of soil per unit volume, which affects root penetration, water movement, and aeration.
704
Why is it bad if soils become too waterlogged?
## Footnote
Hypoxic envitonments. Two things are prevented.
**Anaerobia**
* Soil water levels above the field capacity will not allow soil aeration and create a hypoxic environment.
* This will limit respiration in the roots and root crown as well as the decomposition of organic matter into humus.
705
What is the formula for glucose?
C6H12O6
706
Why does adding organic matter to a soil increase the soil's ability to hold water?
Because organic matter binds the soil into aggregates and holds water, increasing retention.
707
Why does increasing light intensity increase the rate of evapotranspiration?
## Footnote
Something opens up wider...
The stomata open wider to allow more carbon dioxide into the leaf for photosynthesis.
708
What do ATP and NADPH do together?
They create glucose. They do this by "fixing" carbon with the addition of extra ions from NADPH.
