Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HL Bio > 9 plants (bioninja summary) > Flashcards

9 plants (bioninja summary) Flashcards

1
Q

the structure of a plant is related to…

A

its FUNCTIONS
eg Roots are highly branched, with a high SA:Vol ratio
(necessary for water and mineral uptake)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Leaf Tissue 2

A
  • Palisade mesophyll – upper layer of tightly packed
    cells that are rich in chloroplasts (⇧ light absorption)
  • Spongy mesophyll – lower layer of cells interspersed
    by space and located near the stomata (⇧ gas exchange)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Root systems adaptation

A

extensive branching in order to maximise the available surface area for material uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Fibrous (adventitious) root systems

A

many branching roots that are thin and very spread out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • Tap root systems
A

deeply penetrating central root (for stability)
with many connected lateral branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

root hairs

A

small extentions on root epidermis (to further increase available surface area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

organisation of vascular bundles differ according to..

A

plant section (root vs stem) and plant type (monocot vs dicot)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

vascular bundle distribution in roots

A

Vascular bundles are radially arranged within a big stele in monocots, but are centrally arranged within a small stele in dicots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

vascular bundle distribution in stems

A

Vascular bundles are scattered haphazardly in monocots, but form a ring around a circular cambium in dicots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

dicot root vs monocot root

A

dicot: ‘x’ in the middle (phloem), scattered xylem,
monocot: ring in the center, xylems outwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

dicot stem vs monocot stem

A

di: single ring lining inner wall
mono: scattered around, most around inner wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is transpiration + 3 basic steps

A

Transpiration is the loss of water vapor from a plant
* Active uptake of ions by roots promotes water uptake
* Water moves up the stem of a plant by mass flow
* Water is evaporated from leaves (via stomatal pores)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

transpiration stream

A

flow of water from root to leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how and what do roots uptake 4

A
  1. Soil contains anionic clay particles to which minerals attach
  2. Roots pump H+ ions into the soil to displace the minerals
  3. Displaced minerals diffuse into root (indirect active transport)
  4. Water follows mineral ions into the root via osmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does mass flow work

A

water moves up stem in xylem vessels

  • Pressure is high in root (water in) and low in leaf (water out)
  • The pressure differential results in the mass flow of water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what forces are part of capillary action?

A
  • Cohesion (water molecules stick together by H-bonding)
  • Adhesion (water molecules adhere to the xylem wall)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

transpiration is a consequence of?

A

gas exchange in the leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how do guard cells manage transpiration rate

A

turgid – open (K+ ions pumped in, water moves in)
flaccid – closed (water moves out)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

drawing of xylem structure

A

l spiral ll rings l l – l (sieve plates)
xylem has little gaps + little protrusions in the cell walls (pits)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

water conservation adaptations Xerophytes (desert plants)

A
  • Reduced leaves (lowers evaporative SA)
  • Thick, waxy cuticles (reduces water loss from leaves)
  • Stomata in pits with hairs (traps vapor = ⇩ evaporation)
  • CAM physiology (only opens stomata at night)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

water conservation adaptations Halophytes (salt water plants)

A
  • Cellular sequestration (salt is stored within the vacuoles)
  • Tissue partitioning (abscission of leaves containing salt)
  • Salt excretion (salt is actively removal from the plant)
  • Root level exclusion (roots avoid salt uptake)
22
Q

modelling of water transport in xyelm 3 ways

A
  • Capillary tubing (water moves along tubing via surface tension)
  • Filter paper (absorbs water due to adhesive properties)
  • Porous pots (semi-permeable containers can model osmosis)
23
Q

transpiration measurement

A

potometers
* measure movement of air bubble
* More movement= incr transpiration rate

24
Q

xylem vs phloem strcutre

A

Process
Transpiration // Translocation

Materials
Water, minerals // Organic nutrients

Transport
Unidirectional // Bidirectional

Composition
Vessel element and tracheid //
Sieve element and companion cell

Structure
Dead cells form a hollow tube //
Living cells form a tube with plates

Location
Inner or central region of bundle
// Outer region of vascular bundle

25
Q

measurement of translocation rate

A

aphids feed on sap in phloem
radioactive co2 = radioactively labelled sugars
time taken for radioisotopes to be detected = rate of t

26
Q

what are meristems

A

Meristems are undifferentiated cells in plants that are capable of indeterminate growth (analogous w totipotent stem cells)

  • They have specific regions of growth or development and allow for regrowth and vegetative propagation
27
Q

2 types of meristem tissue

A

Apical and Lateral

28
Q

apical meristem

A

Occurs in shoots and roots and is responsible for primary growth (i.e. lengthening) and leaf development

29
Q

lateral meristem

A

Occurs at the cambium and is responsible for secondary growth (i.e. widening) and the production of bark

30
Q

what are auxins

A

plant hormones control growth in auxins (stimulate/inhibit cell div)

31
Q

how are differentiated growth rates generated in plant tissue

A

Auxin efflux pumps can set up concentration gradients of auxin in plant tissues

32
Q

where does auxin come from and what does it coordinate

A

released by the shoot apical meristem

coordinates both apical growth and directional growth (tropism)

33
Q

how does auxin influence cell growth rates

A

by changing the pattern of gene expression within the plant tissue

34
Q

apical dominance

A

Auxins promote growth in apex but inhibit growth in buds

35
Q

how are axillary buds formed

A

growth occurs in sections (nodes), remaining meristem tissue forms inactive axillary buds – potential to form new shoots

36
Q

what is a tropism

A

the turning of an organism in response to a
directional external stimulus (e.g. light = phototropism)

37
Q

how do plant tropisms happen

A

the differential elongation of
plant cells (plant turns away from side with cell elongation)

38
Q

role of auxin in tropisms in shoots and roots

A
  • In plant shoots, auxin promotes cell elongation
  • In plant roots, auxin inhibits cell elongation
39
Q

what is micropropogation

A

technique used to produce large numbers of
identical plants (i.e. clones) from a selected stock plant

40
Q

uses of micropropogation 3

A
  • rapid bulking up of new plant varieties
  • production of virus-free strains of existing varieties
  • propagation of rare plant species
41
Q

3 stages of sexual repro in flwoering plants

A
  • Pollination – transfer of pollen from the anther to the stigma (usually between different plants)
  • Fertilisation – fusion of the male gamete nuclei (in pollen) with the female gamete nuclei (in ovule)
  • Seed Dispersal – fertilised ovule (seed) moves away from the parent plant to reduce the competition for growth
42
Q

components of pistil

A

female

stigma
style
ovule

43
Q

components of stamen

A

male

anther
filament

44
Q

seed strcutre 5

A

little leaf = epicotyl
little stem/bulb = radicle
seed indent = microphyle
main body = cotyledon
opposide side of indent = testa

45
Q

what is germination

A

the process by which a seed emerges from a
period of dormancy and sprouts (forming a new plant)

46
Q

what is needed for germination 3

A
  • Oxygen (to produce ATP via aerobic respiration)
  • Water (to metabolically activate the cells)
  • Suitable temperature and pH (for enzyme activity)
47
Q

what is photoperiodism

A

The response of a plant to the length of day or night

controls flowering

48
Q

2 forms of the phytochrome

A
  • sunlight – Pr –> Pfr (fast)
  • night – Pfr –> Pr (slow)
49
Q

flowering requires…

A

a set length of uninterrupted darkness

50
Q

long day plants

A
  • Pfr activates flowering
  • Flowering induced when night length is SHORT (⇧ Pfr)
51
Q

short day plants

A
  • Pfr inhibits flowering
  • Flowering INDUCED when night length is long (⇩ Pfr)

HL Bio (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions