B4e - transport in plants

Question 1

What is the function of xylem?

Answer 1

Transpiration- movement of water and minerals from the roots to the shoot and leaves

Question 2

What is the function of phloem

Answer 2

Translocation- movement of food substances (sugars) up and down stems to growing and storage tissues

Question 3

What is the structure of xylem?

Answer 3

Xylem vessels are thick strengthened cellulose cell walls with a hollow lumen (dead cells)

Question 4

What is the structure of phloem?

Answer 4

Columns of living cells

Question 5

What is transpiration?

Answer 5

The evaporation and diffusion of water from inside leaves

Question 6

Where do xylem and phloem form continuous systems?

Answer 6

Leaves, stems and roots

Question 7

What makes the transpiration rate faster?

Answer 7

• increase in light intensity
• increase in temp
• increase in air movement
• decrease in humidity

Question 8

What increases the ability of roots to take up water by osmosis

Answer 8

Root hairs

Question 9

Why do plants need transpiration?

Answer 9

• cooling
• photosynthesis
• support
• movement of minerals

Question 10

How is the structure of a leaf adapted to reduce excessive water loss?

Answer 10

• waxy cuticle (stomata is more blocked up)

- small number of stomata on upper surface (when the stomata is smaller, less water is lost through it)

Question 11

How is the cellular structure of a leaf adapted to reduce water loss?

Answer 11

• changes in guard cell turgidity (due to light intensity and availability of water) to regulate stomata apertures
• number, distribution, position and size of stomata