Topic 6

Question 1

What is the equation for photosynthesis?

Answer 1

6CO2 + 6H2O → 6O2 + C6H12O.
Carbon dioxide+water→oxygen+ glucose

Question 2

What affects the rate of photosynthesis?

Answer 2

• Light intensity
• CO2 concentration
• Temperature

Question 3

What does the xylem carry?

Answer 3

Water and minerals.

Question 4

What does the Phloem carry?

Answer 4

Organic molecules and food substances e.g. sugar/ amino acids.

Question 5

What is the difference between xylem and phloem tubes?

Answer 5

Phloem:
- End walls.
- Walls are made of living cells.
- Transports both ways.
- Does translocation.
Xylem:
- No end walls.
- Walls are made of dead cells.
- Transport upwards.
- Does transpiration.

Question 6

What is transpiration?

Answer 6

The evaporation and movement of water away from the plant’s leaves from the inside of the plant.

Question 7

How does an auxin work in the tip of a plant?

Answer 7

They accumulate on the shaded side causing it to grow faster and bend towards the light.

Question 8

How does an auxin work in the root of a plant?

Answer 8

An auxin in the root will inhibit growth and accumulate on the lower side so the root bends downwards

Question 9

What are the different types of growth in shoots and roots?

Answer 9

Positively Phototropic- Grow towards light.
Negatively Gravitropic- Grow away from gravity.

Positively Gravitropic- Grow towards gravity.
Negatively Phototropic- Grow away from light.

Question 10

What are plant hormones used for?

Answer 10

• Selective weedkillers.
• Growing from cuttings with rooting powder.
• Controlling flower and fruit formation.
• Producing seedless fruit.
• Controlling ripening of fruit.
• Controlling seed germination.