1. What affects how well a plant grows?
Limiting factors
What affects how well a plant grows?
Starter: why is this tree so much taller than the others?!

2. Success criteria name the factors that limit plant growth.
explain how the factors limit plant growth.
What affects how well a plant grows?

3. Think, pair, share
Group 1: what are the best conditions for plants to grow?
Group 2: where do plants get their resources from?
Group 3: why do most plants not keep getting bigger and bigger and bigger?
What affects how well a plant grows?

4. Photosynthesis and light – limiting factors
How does the amount of light affect the rate of photosynthesis on this labelled graph?
As the amount of light increases, so does the rate. 1 2 2
Here, increasing the amount of light has no affect on the rate. The limiting factor is now carbon dioxide or temperature.
What must be increased for the rate to increase?
rate of photosynthesis 1
light intensity
What factors affect how well a plant grows?

5. Photosynthesis and carbon dioxide – limiting factors
How does the amount of carbon dioxide affect the rate of photosynthesis on this labelled graph? 1
As the amount of carbon dioxide goes up, so does the rate. The limiting factor is carbon dioxide. 2 2
Here, increasing the amount of carbon dioxide has no affect on the rate. Light or warmth is now the limiting factor.
What must be increased for the rate to increase?
rate of photosynthesis 1
concentration of
carbon dioxide
What factors affect how well a plant grows?

6. Photosynthesis and temperature – limiting factors
How does temperature affect the rate of photosynthesis on this labelled graph? 1
As temperature increases, so does the rate because photosynthetic enzymes work best in the warmth. Here, the limiting factor is temperature.
rate of photosynthesis 2
Most plant enzymes are destroyed at about 40°C. Here, photosynthesis stops and the rate falls to zero.
What is the limiting factor? 2 1
0oC
temperature
45oC
What factors affect how well a plant grows?

7. Check point Use the Call my bluff cards. Are you True or Bluff?
Write a TRUE or BLUFF definition we can play with.

8. Check point Which of these is not a limiting factor? 1: temperature
2: Glucose
3: light
What affects how well a plant grows?

9. Task Collect your plant superheroes.
Use the postit note to answer the following.
1) What are the limiting factors?
2) What impact do these have on your character?
3) How can they overcome them?
What affects how well a plant grows?

10. Limiting factors Complete the worksheet looking at these graphs.
Name the factors that limit plant growth.
Explain how the factors limit plant growth.
Limiting factors
Complete the worksheet looking at these graphs.
What factors affect how well a plant grows?

11. Think, pair, share
Plants that grow in a green house can be provided with resources.
What should they be given and how would you provide it.
What affects how well a plant grows?

12. Task
Work through the past paper questions. Answer blanks. Mark the filled in answers using the marking scheme.
What affects how well a plant grows?

13. Plenary
Write an exam question of your own for limiting factors.

14. Call my bluff
Limiting factor – a factor which limits the rate of photosynthesis due to its lack of abundance.
Limiting factor – a factor which is at its limit and therefore cannot increase further.
Limiting factor – a factor which cannot be controlled and therefore limits what can be achieved.
What affects how well a plant grows?