Transport In Plants

Question 1

Function of xylem

Answer 1

1. Conducting water and dissolved mineral salts from the roots to the stems and leaves
2. Providing mechanical support for the plants

Question 2

How is the xylem vessel adapted for its function?

Answer 2

1. The xylem vessel has an empty lumen without protoplasm to reduce resistance to water flowing through the xylem from the roots to other parts of the plant.
2. Its walls are thickened with lignin. Lignin is a hard and rigid substance and it helps to preclude the collapse of the xylem vessel.

Question 3

Function of phloem and its adaptation

Answer 3

To transport manufactured food from the leaves to other parts of the plant.
Adaptations:
1. Companion cells have many mitochondria to release energy from aerobic respiration to carry out active transport.
2. The holes in the sieve plates allow rapid flow of manufactured food from the leaves to other parts of the plant

Question 4

How is the root hair adapted to its function of absorption?

Answer 4

1. The root hair is long and narrow—>increases surface area to volume ratio—>increases rate of absorption of water and mineral salts.
2. The root hair cell contains many mitochondria—> aerobic respiration in the mitochondria releases energy for active transport of mineral ions into the cell.

Question 5

What is the definition of transpiration?

Answer 5

Transpiration is the loss of water vapor from a plant, mainly through the stomata of the leaves.