Transport in plants

Question 1

State the functions of the xylem and phloem

Answer 1

Xylem - Transport of water and mineral ions
Phloem - Transport of sucrose and amino acids

Question 2

How is the structure of a xylem vessel related top its function?

Answer 2

Thick walls with lignin/keeps the plant upright
No cell contents
Cells joined end to end to form a continuous tube

Question 3

What is the importance of a large surface area in the roots

Answer 3

Increases the uptake of water and minerals

Question 4

Outline the pathway taken by water through the roots

Answer 4

Root hair cells –> Root cortex –> Xylem –> Mesophyl cells.

Question 5

Define transpiration

Answer 5

The loss of water vapor from the leaves

Question 6

What are the effects of different temperatures, humidity wind speeds on the rate of transpiration?

Answer 6

The higher the temperature the higher the rate of transpiration
The windier it is the lower the rate of respiration
Humidity: the higher the moisture content, the lower the rate of transpiration

Question 6

How does water get lost in a leaf

Answer 6

Evaporates from the surfaces of the mesophyll cells into the air spaces and then diffuses out through the stomata.

Question 7

Define translocation

Answer 7

The movement of sucrose and amino acids through the phloem from the source to the sink

Question 8

Define source and sink

Answer 8

Source: parts of a plant that secrete amino acids
Sink: Parts of a plants that receive and use amino acids