Topic 6a - Plant structure & nutrient support Flashcards Preview

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Flashcards in Topic 6a - Plant structure & nutrient support Deck (28):
1

Non-vascular plants include...

liverworts
mosses

2

Vascular plants include...

Ferns
gymnosperms & angiosperms (seed plants)

3

Monocot characterisation...?

flowers in threes
leaves - smooth parallel veins
stems - scattered vascular bundles
roots - fibrous
seeds - 1 cotyledon (seed leaf)

4

Dicot characteristics...?

flowers - 4's or 5's
leaves - net-like veins
stems - vascular bundles form ring around stem
roots - taproot system
seeds - 2 cotyledons (seed leaves)

5

Characteristics of Meristem cells...

undifferentiated
divide mitotically -> meristem cells and/or differentiated cells

6

Characteristics of differentiated cells...

mature
specialised for specific functions

7

Apical meristems are located where? Resultant growth termed...?

located at tips of roots & shoots
...termed primary growth -> develops into leaves & buds

8

Lateral meristems located... Resultant growth termed...?

around perimeter of stems, roots & branches
...termed secondary growth

9

3 main plant tissue systems?

- dermal (outer)
- ground (mid)
- vascular (inner) typically

10

A bit more on dermal tissue... (location, function, types)

outermost layer
primarily protective
2 main types - epidermis (young), periderm (older)

11

A bit about ground tissue...

The "meat" of the plant. (middle)
3 types

12

What are the 3 types of ground tissue? Function? Eg's?

parenchyma - photosynthesis, nutrient storage, hormone secretion (eg potato)
collenchyma - mainly support (e.g. celery stalk)
sclerenchyma - mainly support & protection (e.g. pear)

13

Vascular tissue... function? types?

vessels transporting water & nutrients thru plant
2 types - xylem & phloem

14

Functions of xylem... types?

transport of water & minerals from roots to shoots via pores
2 types of vessels - tracheids & vessel elements

15

Function of phloem? types?

transport dissolved nutrients & hormones (in any direction)
2 types - sieve tube elements & companion cells

16

A bit about stems... functions

support for leaves (major function)
Also transport water, nutrients & photosynthate

17

Dicot stem - primary growth functions...

support
storage (starch)
photosynthesis

18

Difference between primary & secondary growth of dicot stems?

primary has: primary phloem & xylem & vascular cambium
secondary has: primary AND secondary phloem & xylem AND DIVIDING vascular cambium

19

Roots functions?

anchor the plant
uptake & storage of water & minerals

20

Nutrients in roots taken up by ... transport?

active

21

Define rhizosymbionts...

assist roots in nutrient uptake
2 kinds - mycorrhizae & nitrogen-fixing bacteria

22

Water enters ... via ...?

root xylem via osmosis

23

What is transpiration? What 'theory' is involved?

mechanism allowing transport of water many meters to leaves
"cohesion-tension" theory involved

24

Describe "cohesion-tension" theory. Out loud!

Water enters vascular cylinder of root -> cohesion of water molecules via H-bonds creates water chain -> evaporates thru stomata

25

What is stomatal control of transpiration? Involves a balance between ...?

allowing entry to CO2 & allowing loss of water

26

Explain water transpiration via stomatal opening (looks like green anus)...

K+ enters guard cells -> water follows -> guard cells lengthen & bend outward -> pore (green anus) opens

27

What stimulates movement of K+ (re. stomatal opening)?

light (movement inward)
low CO2 (inward)
absidic acid (outward)

28

Describe pressure-flow theory...

sugars move to sites of high [ ] (sources) -> sites of low [ ] (sinks) how??
high [ ] of sugar at source draws water in by osmosis -> increase pressure
[ ] of sugar decreased at sinks
thus pressure differential causes net movement from source to sink