Unit C Cycling of Matter in Living Systems : Section 3.0 Flashcards
(156 cards)
1
Q
What are the advantages and disadvantages of having a large structure?
A
- Division of labour is an advantage and disadvantage
- large size is a disadvantage for nutrient transportation but advantage if it has a system that transports nutrients more effectively
- Interdependence of cells could be a disadvantage but also an advantage
2
Q
How is division of labour an advantage?
A
-Specialized cells perform more efficiently
3
Q
How is a large cell size a disadvantage?
A
- slower rate of diffusion (The surface area to volume ratio and the related rate of diffusion restricts the size of unicellular organisms)
4
Q
How is size an advantage?
A
- In multicellular organisms, internal support structures, that can exist due to the large size of the organism, allow for the efficient exchange of materials, allowing further growth
5
Q
How is the interdependence of cells an advantage in multi-cellular organisms?
A
-If one cell dies the organism can still function
6
Q
How is the interdependence of cells a disadvantage in multi-cellular organisms?
A
If one cell malfunction it could be possible that as the problem increases the whole organism could suffer
7
Q
What are tissues?
A
Groups of cells performing the same function together
8
Q
What are organs?
A
Tissues contributing to the same function
9
Q
What are Systems?
A
A set of organs that perform a function
10
Q
What are the 2 organ systems of a plant
A
- Shoot System
- Root System
11
Q
What is the shoot system?
A
Every part of the plant above the ground
12
Q
What is included in the shoot system of a plant?
A
Stem Leaves Buds Flowers Fruits *Tubers*
13
Q
What are tubers?
A
Enlarged, underground stem that stores food
14
Q
What is the root system?
A
Every part of the plant that is underground
15
Q
In plants, why do cells divide?
A
The growth of new tissue and repair of damaged tissue
16
Q
What is mitosis?
A
The process of cell division that allows growth and repair. One cell divides into two cells
17
Q
What are meristems?
A
Regions in plants where cell division occurs
18
Q
What are the 4 types of tissues in plants?
A
- Dermal/Epidermis tissue
- Ground tissue
- Vascular tissue
- Phloem tissue
19
Q
What is Dermal/Epidermis tissue?
A
-The outer layers of cells that covers all non-woody plants
20
Q
How many cells thick is the Dermal/Epidermal tissue?
A
1 cell layer thick
21
Q
What is the Dermal/Epidermal Tissue responsible for?
A
The exchange of matter and gasses in and out of the plant
22
Q
What is the Epidermis in woody plants?
A
It is replaced by cork and bark during the secondary growth stage and development
23
Q
What system is the Dermal tissue a part of?
A
The Shoot System
24
Q
What does the Dermal tissue do in the shoot system?
A
- Primarily involved in gas exchange of carbon dioxide and oxygen
- Protects plants from disease
25
What do the cells of leaves secrete?
A waxy substance called the cuticle
26
What does the cuticle do?
- Resists attack from micro-organisms
- Helps to reduce water loss from the plant
27
What is Dermal tissue in the root system responsible for?
Responsible for the uptake of water and mineral salts from the soil
28
What is the layer of tissue underneath the epidermis called?
Ground tissue
29
Which tissue makes up the majority of the plant?
Ground tissue
Often times, tissues that are not considered dermal or vascular tissue are noted as ground tissue. These cells store molecules (such as starch), photosynthesize (such as mesophyll cells), or support the plant. There are three types of ground tissue: collenchyma, sclerenchyma, and parenchyma
30
What does ground tissue do in the stem?
It provides strength and support for the plant
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What does ground tissue do in the roots?
It is involved in food and water storage
32
What occurs in ground tissue in leaves?
Photosynthesis occurs
33
How are the cells in ground tissue arranged?
They are loosely packed together
34
How does ground tissue help with diffusion?
Because they are loosely packed together the large spaces allows gas to diffuse rapidly
35
What is Vascular tissue responsible for?
It is responsible for the transport of materials throughout the plant
36
What are the 2 types of vascular tissue?
Xylem tissue
Phloem tissue
37
What does Xylem tissue do?
Moves water and dissolved minerals from the roots up the stem to the leaves
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What are the substances, that the Xylem tissue transports, used for?
Photosynthesis
39
What does Xylem tissue look like?
Thick-walled tubes of varying diameters
40
What is the thickening of Xylem tube walls the result of?
Cellulose and lignin being deposited on the cell wall
41
How does Xylem tissue come to be?
- As cylindrical cells mature, they fuse together and the walls at each end become perforated
- As a result, the contents of the cytoplasm break down and the cells die leaving non-living cell walls attached to each other
42
Is the Xylem tissue living?
No
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What does Phloem tissue do?
Transports sucrose and other dissolved sugars from the leaves to other parts of the plant cell
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What is Phloem formed from?
From individual long sieve tube cells
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What do sieve tube cells have?
Perforated walls through which cytoplasm extends
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What is interesting about Sieve tube cells?
They remain alive but lose their nuclei
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What are Sieve tube cells connected to?
Companion cells
48
What do companion cells do?
They direct the other cells cellular activities
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Why are sugars transported? What are they used for?
They are used to provide energy for cellular processes such as protein manufacture
50
What does cellulose form?
Fibrous structures for strength and support and may become associated with the formation of wood
51
How are the sugars in plants stored?
As starch in roots, stems, or leaves
52
What type of cells are root hairs?
Specialized cells
53
What are root hairs?
Hair like projections on cells that are a part of the root system. The root hairs increase surface area for the absorption of water.
54
What does the lower epidermal surface of leaves produce?
Guard cells that form tiny pores called stomata for gas exchange
55
What is interesting about guard cells?
They are the only cells in the epidermis that contain chloroplasts
56
Which place has more stomata? The upper epidermis or the lower epidermis?
The lower epidermis
57
Why does the upper epidermis have fewer stomata?
So that there is less water loss
58
What are the 3 main types of tissue?
Thermal
Ground
Vascular
59
What is the green pigment in chloroplasts called?
Chlorophyll
60
Where are cells containing chloroplasts found?
In the ground tissue of leaves and sometimes stems
61
What is the organelle where a plant carries out photosynthesis called?
Chloroplasts
62
Where does carbon dioxide for photosynthesis come from?
Air
Water
Soil
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What is the word formula for photosynthesis?
carbon dioxide + water —> glucose + oxygen
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What are the reactants for photosynthesis?
Water and Carbon dioxide
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What are the products of photosynthesis?
Glucose and Oxygen
66
What happens in photosynthesis?
Light energy is absorbed by the chlorophyll and converted into chemical energy
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Where is the chemical energy from photosynthesis stored?
In the molecules of glucose
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What are not considered to be reactants in photosynthesis?
Light and chlorophyll
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What does cytoplasmic streaming do?
Circulates materials and speeds of their distribution within the cell
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What is the light energy in photosynthesis stored as?
Chemical energy within glucose
71
Where does cellular respiration happen?
It begins in the cytoplasm but is completed in the mitochondria
72
What is the word formula for cellular respiration?
glucose + oxygen —> carbon dioxide + water + energy
73
What process of the plant only occurs in the day?
Photosynthesis
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How do Stomata work?
They open into air chambers that connect with the cells of the ground tissue
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How do carbon dioxide and oxygen leave and enter the leaf?
Through diffusion from the Stoma
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Where are the majority of Stoma found?
On the underside of a leaf next to epidermal cells
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What is the order of tissue on plants?
Cuticle
Epidermis
Ground
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What are stomata made of?
Guard cells
79
How do guard cells work?
They swell up to open the stomata and shrink away to close the stomata
80
How do Stoma a work?
Light striking the leaf triggers the guard cells to accumulate potassium ions by active transport and as a result, water enters by osmosis and they swell up
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What are guard cells function?
- To allow materials in and out when necessary
| - Protect leaves from losing too much water
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What is transpiration?
The process of water vapor leaving the leaf
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Why would a plant have less Stoma?
To adapt to living in a hot dry climate with low humidity
84
What tissue is between the upper epidermis and the lower epidermis?
Specialized tissue called mesophyll
85
What are the types of mesophyll/ground tissue?
- Palisade tissue cells
| - Spongy mesophyll tissue
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Where are palisade tissue cells found?
Just below the upper epidermis
87
What do palisade tissue cells look like?
Long, rigid, rectangular cells that are tightly packed and arranged so that a large number of cells are exposed to the suns rays
88
What are the palisade tissue cells responsible for?
They are responsible for photosynthesis, so they have many chloroplasts in them
89
Where are the spongy mesophyll tissue cells found?
In between the palisade tissue cells and the epidermis tissue
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What do the spongy mesophyll tissue cells look like?
Loosely packed, irregularly shaped, and less rigid
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What is the primary function of the spongy mesophyll tissue?
Gas exchange by diffusion throughout the leaf. They will move oxygen towards the stomata and carbon dioxide toward that palisade cells
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What are leaf veins?
The network of vascular tissue running through it
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What is a vascular bundle?
The network of Xylem and Phloem bunched together
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Where can diffusion of gasses other than the leaf happen in plants?
Pores along the wood stems and mature roots of plants called lenticels
95
What is Cohesion?
The attraction of water molecules to other water molecules
96
Why does water demonstrate Cohesion?
Because water is polar. It is slightly positive and slightly negative so it attracts other molecules of water
97
What is adhesion?
The attraction of water molecules to other molecules of a substance
98
How is root pressure created?
- Dissolved minerals are present in the cell due to active transport
- This creates a hypertonic concentration inside the cell
- The hypertonic solution draws in water by osmosis
- The water creates positive pressure which forces the fluid up the xylem into the low-pressure leaves
99
What does root pressure do?
Root pressure moves water from the roots of the plant to the leaves of the plant
100
What is the maximum root pressure can move water?
A maximum of only a few meters
101
What is the overall water movement process affected by?
Transpiration
102
Where does transpiration occur?
At the stomata
103
How does transpiration affect the plant?
As water is lost in the stem and leaves it must be replaced, and so water is drawn from the roots to the pant
104
Why are only certain cells dyed when a plant is placed in colored water?
Because water only flows through the xylem cells
105
How do substances have to be to be transported in plants?
They have to be dissolved in a film of water
106
What are the differences in pressure caused by in a plant?
Osmosis and Transpiration
107
How are minerals absorbed into plants?
By the root hairs by active transport
108
How does water enter the roots of a plant?
Through osmosis
109
What does the osmosis of water into the xylem tissue create?
Root pressure
110
What does root pressure do?
It forces water through the cells along the cell wall into the xylem
111
What is transpiration?
The evaporation of water through the stomata and lentils
112
What does transpiration create?
Tension or Transpiration pull
113
How does Tension or Transpiration pull work?
As water molecules evaporate it creates a pull on the other water molecules
-Then combined with the forces of cohesion and adhesion, the pull is enough to draw water up the xylem and into the leaf
114
What happens once the water is drawn up the xylem and into the leaf?
The water moves into the ground tissue
115
How does transpiration depend on temperature?
-If the temperature is high the rate of evaporation through the stomata will be high and the water movement in the xylem will be rapid
116
How high can water rise per a minute?
75 cm
117
What is the remaining water in the leaf used for?
It is used to manufacture sugars through photosynthesis and then the sugar is moved into the phloem
118
What is Tonicity?
The concentration of solute particles in a solution
119
What effect do changes in tonicity have on a plant?
They affect osmosis and the arrangement of structures in plant cells
120
What is plasmolysis?
The shrinking of the cytoplasm and membrane away from the cell wall due to outflow of water to a hypertonic environment
121
What is the outward effect of plasmolysis?
The leaf appears wilted or limp
122
What causes plasmolysis?
When water moves out of the cell in a hypertonic environment
123
What happens if a plant in a hypertonic solution is returned to fresh water?
The cells draw in more water end the cell is said to become turgid and cannot let any more water flow in
124
Why is turgidity important in plants?
It is important because it holds the green parts up toward sunlight
125
What is a critical process for plants?
Phloem transport
126
What are some ways phloem can be killed?
- Dehydration
| - Excessive heat
127
What does phloem do?
It takes the products of photosynthesis from the leaves to the place where they will be stores, the sink
128
What is the sink?
The place where the products of photosythesis can be stored
129
What do sieve tube cells depend on?
Companion cells
130
What tissues are made out of sieve tubes?
Phloem
131
What do sieve tube cells depend on companion cells to do?
The movement of sugars into and out of sieve tube cells
132
How does the phloem become loaded with sugar molecules?
The companion cells use carrier proteins and active transport
133
How are glucose molecules moved into the plant?
Pressure Flow Theory
- When glucose enters the plant water molecules also enter the plant through osmosis
- The increased pressure inside the cells pushes water and sugar through the phloem to the rest of the plant and up at a sink
134
What are some forms of a sink?
Root
Tuber
Fruit
135
How do sugars reach other cells from the sieve tube cells?
The actively transported across cell membranes
136
What are the sugar molecules used for?
Growth, respiration, and other life processes
137
What happens as water leaves the sieve cells?
More water and sugar is pushed in the cells
138
What maintains a constant flow of food down the sieve tube?
The pressure differences produced by active transport and osmosis
139
What are stimuli?
A change in the environment that results in a reaction from an organism
140
What is phototropism?
When plants grow toward the light
141
What type of phototropism do stems exhibit?
Positive phototropism
142
What type of Phototropism do roots exhibit?
Weak negative phototropism because they grow away from the light
143
What is gravitropism?
Plant growth in response to gravity
144
What type of gravitropism do stems exhibit?
Negative gravitropism because they grow against the force of gravity
145
What type of gravitropism do roots exhibit?
Positive gravitropism
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What is another name for gravitropism?
Geotropism
147
What do tropisms do?
Ensure survival of a plant
148
Which scientists conducted experiments about phototropism?
- Charles Darwin
- Peter Boysen-Jensen
- F.W. Went
149
What plant did the scientists who studied phototropism study?
The oat plant
150
What covers developing leaves?
An outer sheath
151
How high does the sheath grow in an oat or grass?
4-6 cm
152
What happens to a plant if the light only comes in one direction?
The sheath will bend towards the light source
153
Which part of the plant is responsible for the detection of stimulus?
The tip of the stem
154
What is the photoropic response created by?
The elongation of sheath cells
155
What is auxin?
The hormone produced in the tip of the plant responsible for the reaction of phototropism
156
How do plants know which way gravity is?
Plants rely on starch molecules in specialized cells
