2.2 - Limiting factors

Question 1

How does light intensity affect the rate of photosynthesis?

Answer 1

• A lack of light slows down the rate of photosynthesis

- The higher the light intensity, the faster the rate of photosynthesis, up to a point where it plateaus

Question 2

Why does a lack of light slow down the rate of photosynthesis?

Answer 2

The light provides the energy for the process

Question 3

How does temperature affect the rate of photosynthesis?

Answer 3

• If it is cold, the rate of photosynthesis slows down
• If the temperature increases, the rate of photosynthesis increases steadily up to a certain point, when the reaction stops and the rate drops to zero

Question 4

Why does the rate of photosynthesis slow down when it is cold?

Answer 4

The enzymes do not work effectively

Question 5

Why does photosynthesis stop when the temperature becomes to high?

Answer 5

The enzymes are destroyed, so the reaction stops

Question 6

How does carbon dioxide concentration affect the rate of photosynthesis?

Answer 6

• If there is too little carbon dioxide, the rate of photosynthesis will slow down
• The higher the concentration of carbon dioxide, the faster the rate of photosynthesis, until it plateaus at a certain light level and temperature. Eventually one of the other factors becomes limiting

Question 7

What is a limiting factor?

Answer 7

Anything that puts a cap on the rate of a reaction, eg photosynthesis

Question 8

What are three limiting factors of photosynthesis?

Answer 8

1) Lack of light
2) A low temperature
3) A low concentration of carbon dioxide

Question 9

When might carbon dioxide be limited for a plant?

Answer 9

In an enclosed space, e.g in a greenhouse on a sunny day when there is plenty of light energy available but plants run out of carbon dioxide

Question 10

What is the independent variable?

Answer 10

What is being tested

Question 11

What is the dependent variable?

Answer 11

What is being measured