Biology: Xerophytes

Question 1

What are Xerophytes?

Answer 1

highly adapted plants to prevent water loss when stomata are open

Question 2

Why is a small leaf an important adaptation?

Answer 2

reduced surface area for evaporation

Question 3

Why is sunken stomata an important adaptation in Xerophytes?

Answer 3

maintains humid air around stomata to reduce water potential gradient

Question 4

Why are stomatal hairs an important adaptation in Xerophytes?

Answer 4

maintains humid air around stomata to reduce evaporation and water potential

Question 5

Why are rolled leaves an important adaptation to Xerophytes?

Answer 5

reduces effect of wind to reduce water potential and evaporation

Question 6

Why are extensive root systems an important adaptation in Xerophytes?

Answer 6

maximises water uptake / wide area to absorb rainfall / swollen stems to store collected water

Question 7

Outline the structure of a dicotyledonous

Answer 7

stomata on lower side, net-like veins, palisade and spongy mesophyll

Question 8

Outline the structure of monocotyledon

Answer 8

stomata upper and lower side of leaf, veins run parallel to one another

Question 9

Why is a reduced number of stomata an important adaptation in Xerophytes?

Answer 9

reduce places water can evaporate from

Question 10

Why is a thicker, waxy cuticle an adaptation in Xerophytes?

Answer 10

waterproofs leaves and stems to reduce evaporation

Question 11

How can we investigate stomatal density?

Answer 11

-examining thin layers of epidermis or ‘imprints’ of leaf
-multiple sections calculated to determine a mean
-can be scaled to whole leaf