Topic 6

Question 1

Leaf adaptations in layers

Answer 1

Waxy cuticle - prevents water loss
Upper epidermis - transparent so let’s light through
Palisade layer - chloroplasts and mitochondria
Airs spaces and spongy cells - large surface area for gaseous exchange
Lower epidersmis and stoma

Question 2

Stoma adaptations and procedures and function

Answer 2

Mitochondria for energy and few chloroplasts
As water flows into the guard cells they become rigid hence opening stoma
As water flows our they lose rigidity and close at night
Used for co2 in and water vapour and oxygen out

Question 3

Cacti adaptations

Answer 3

Stoma open at night when it is cooler to prevent water loss
Thick cuticle prevents from water loss
Stoma in pits where water vapour collects reducing water loss

Question 4

Movement of water from root to leaves

Answer 4

Osmosis into root hair cell
Osmosis into xylem vessel
Water molecules are drawn up xylem vessel because water evaporating through stoma known as transpiration
As on water molecule evaporates another takes it’s place
Water molecules are held together because of cohesion and don’t falls down because of adhesion.

Question 5

unbroken chain of water due to Cohesion Adhesion theory

Answer 5

Cohesion is the weak forces of attraction between opposite charges wishing the water molecule
Adhesion is the oppositely charged forces between xylem wall and water molecule

Question 6

Xylem adaptations

Answer 6

Dead cells without cytoplasm with top and bottom cell wall disintegrated
Long hollow tube for flow of water
Thick side walls and rings of lignin will not collapse
Tiny pores allow water and mineral ions to enter and leave stoma

Question 7

Lignin

Answer 7

Hard waterproof polymer

Question 8

Translocation how

Answer 8

Phloem tissue
Large central channel of sieve cells where sucrose flows
Companion cells pump sucrose into sieve which increases pressure

Question 9

Companion cell adaptation and sieve cells adaptations

Answer 9

Mitochondria for energy for pumping

Small cytoplasm for easy flow

Question 10

Difference in direction of flow

Answer 10

Xylem flow up

Phloem either way

Question 11

Giberrellins

Answer 11

Seedless fruit
Photoperiodism is where plant responds to number of daylight hours and grows.Giberellins overrides this causing quick growth without seeds

Question 12

Rooting powder

Answer 12

Auxin causes plant cuttings to grow quickly for farmers