T2 plant tissues, organs and systems Flashcards Preview

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Flashcards in T2 plant tissues, organs and systems Deck (17)
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1
Q

how is epidermal tissue adapted for their function

A

epidermal tissue covers the entire plant

has a waxy cuticle which helps reduce water loss from the leaf surface

2
Q

how is palisade mesophyll tissue adapted for its function

A

contain lots of chloroplasts which allows photosynthesis to progress at a rapid rate

3
Q

how is spongy mesophyll tissue adapted for its function

A

has lots of air spaces which allow gases to diffuse in and out

4
Q

how is xylem adapted for its function

A

made up of dead cells which form a continuous hollow tube - allows the movement of water and mineral ions from the roots to the leaves

strengthened by lignin - makes the vessel strong and waterproof

has bordered pits - allow minerals to be transported to specific places

5
Q

how is the phloem adapted for its function

A

made up of elongated living cells

cells have sieve plates that connect them together - cell sap can move through plates into other cells

sieve tube cells have few organelles to allow the efficient transport of substances

6
Q

how is meristem tissue adapted for its function

A

made up of stem cells which can differentiate into many different cell types, allowing the plant to grow

7
Q

what tissues does the leaf organ contain

A
epidermis
palisade mesophyll
spongy mesophyll
xylem
phloem
guard cells
8
Q

function of guard cells

A

control the opening and closing of the stomata, according to the water content of the plant

9
Q

how are stomata adapted for their function

A

allow the control of gaseous exchange and water loss from the leaf

more stomata on the base of the leaf - minimises water loss as this side is cooler and shaded

have guard cells which control their opening and closing

10
Q

how are root hair cells adapted for their function

A

allow the uptake of water and mineral ions from the soil

large SA - maximises rate of absorption

contain lots of mitochondria - release energy for active transport of mineral ions

11
Q

what is translocation

A

movement of dissolved sugars from the leaves to other parts of the plant

12
Q

what is transpiration

A

evaporation of water vapour from the surface of a plant

13
Q

how does transpiration work

A

water evaporates from the leaf surface via stomata

water molecules cohere together - more water is pulled up the xylem in an unbroken column

more water is taken up from the soil - creating a continuous transpiration stream

14
Q

how does temperature affect the rate of transpiration

A

increasing temp, increases rate

higher rate of evaporation and diffusion of water - therefore rate of transpiration is increased

15
Q

how does humidity affect the rate of transpiration

A

increasing decreases

high relative humidity will reduce the water vapour concentration gradient.

Rate of evaporation will decrease, and so will the rate of transpiration

16
Q

how does wind speed affect the rate of transpiration

A

increasing increases

increased air movement lowers water vapour conc outside of the leaf.

this increases the water vapour conc gradient, thereby increasing the rate of evaporation and transpiration

17
Q

how does light intensity affect the rate of transpiration

A

increasing increases

rate of photosynthesis increases, so more stomata open

this allows the rate of evaporation to increase, increasing the rate