Bio Topic 8

Question 1

What does the xylem transport?

Answer 1

Water and minerals

Question 2

What does the phloem transport?

Answer 2

Food (Sugars like sucrose + amino acids)

Question 3

Describe the position of the xylem and phloem in the leaf

Answer 3

The xylem is on the top of the phloem

Question 4

Describe the position of the xylem and phloem in the stem

Answer 4

The xylem is on the inside of the stem

Question 5

“Describe the position of the xylem and phloem in the root
“

Answer 5

“The xylem is in the middle in an X shape
The phloem is on the outside of the xylem”

Question 6

Describe the pathway of water through a plant

Answer 6

“Root hair cell → Root cortex cells → Xylem vessels –> Xylem in the stem→ Mesophyll cells in leaf
“

Question 7

How are root hair cells adapted to their function?(3)

Answer 7

-Long root hair extension to increase surface area
-Thin membranes to decrease the diffusion distance
-lots of mitochondria to release energy for active transport

Question 8

Describe the process of transpiration

Answer 8

“Water is lost through the stomata
More water is drawn up to replace the lost water”

Question 9

Why is water lost from plants? (3)

Answer 9

1) Plants have large air spaces in them
2) Plants have stomata (pores) in the leaves which allows water to diffuse out of the plant
3) Plants have a large surface area for evaporation to occur”

Question 10

Explain the movement of water through a plant

Answer 10

1) evaporation of H2O from Leaves causing shortage of water in leaf
2) water moves into the leaf from the xylem
3) water has strong, cohesive forces so water are is pulled up the xylem
4). Water moved into the roots

Question 11

“How does temperature affect the rate of transpiration?
“

Answer 11

“As the temperature increases, so does the transpiration rate
The molecules have more KE and evaporation happens faster”

Question 12

How does light intensity affect the rate of transpiration?

Answer 12

“The brighter the light, the more stomata are open and the rate of photosynthesis increases which both decrease the amount of water in the plant
The rate of transpiration increases”

Question 13

How does the wind speed affect the rate of transpiration?

Answer 13

The faster the wind speed, the faster the water is moved away from the plant, creating a steeper gradient and increasing the transpiration rate

Question 14

What causes wilting?

Answer 14

A lack of water which means the plant cells are not turgid and so the plant is not supported

Question 15

Describe translocation

Answer 15

Translocation: movement of sugars and amino acids up or down the phloem from source to sink (with the use of energy)

Question 16

What is a source

Answer 16

Part of plant which releases sucrose or amino acids
(Has a higher concentration of sucrose and amino acids)

Question 17

What is a sink?

Answer 17

Any area were sucrose or amino acids are:
-stored
-used up in either respiration or growth

Question 18

When are plant organ sources?

Answer 18

-when plant growing (leaves are actively photosynthesising and producing lots of sucrose)
(Photosynthesis makes glucose which is later on converted to sucrose)

-In the winter when plants lose their leaves storage sites become sources of sucrose

Question 19

When are plant organs sinks?

Answer 19

When plant is growing –> reproductive structures (fruit/flowers) act has sinks

Places where sucrose is stored: roots, tubers, bulbs

In winter, newly growing leaves act as sinks