Factors Which Limit Photosynthesis

Question 1

Things like light intensity can affect the rate of photosynthesis- we call them ______ _____.

Answer 1

Limiting factors

Question 2

Let’s say light intensity is limiting photosynthesis. The only way to increase the rate is to ______ the limiting factor, in this case light intensity.

Answer 2

Increase

Question 3

True or false

Only 1 factor can limit the rate at any time. It depends on which one is in the shortest in supply.

Answer 3

True

Question 4

What is the relationship between temperature and photosynthesis?

Answer 4

As temperatures increase so doe photosynthesis. Except temperatures above 40 degrees as enzymes in photosynthesis are being destroyed.

Question 5

Every plant has an _____ temperature for growth.

Answer 5

Optimum

Question 6

What is the relationship between carbon dioxide and plants?

Answer 6

The more carbon dioxide you give the plants the more photosynthesis they carry out.

Question 7

The air contains about ____ carbon dioxide.

Answer 7

0.04%

Question 8

What are the limiting factors for photosynthesis?(3)

Answer 8

• light intensity
• temperature
• carbon dioxide concentration

Question 9

Factors that influence the rate of photosynthesis:(4)

Answer 9

• Light Intensity
• Temperature
• CO2 concentration
• Water availability

Question 10

How does light intensity affect photosynthesis?

Answer 10

It causes the rate of photosynthesis to increase up to the optimal point. After reaching this optimal point, light intensity will have no effect on the rate of photosynthesis.

Question 11

If light intensity becomes too bright then the ____ close, causing CO2 availability to become a _____ _____ and the process slows down.

Answer 11

Stomata

Limiting factor

Question 12

What is the ideal temperature for photosynthesis?

Answer 12

20-30C

Question 13

What happens if the temperature exceeds this range?

Answer 13

Lower: enzymes become inactive
Higher: enzymes denature

Question 14

What effect does carbon dioxide have on the rate of photosynthesis?

Answer 14

Decrease in CO2 = decrease in rate of photosynthesis

Increase in CO2= increase in rate of photosynthesis

Question 15

Why does a shortage of water effect the rate of photosynthesis?

Answer 15

A shortage of water will decrease turgor pressure causing the stomata to close, limiting gaseous exchange.

Question 16

How do greenhouses increase the rate of photosynthesis?

Answer 16

Increase in temperature,light,carbon dioxide concentration and water

Question 17

How do greenhouses increase temperature?

Answer 17

Using thermostat which controls ventilation and heating systems

Question 18

How do greenhouses increase light?

Answer 18

Translucent materials and use light meters to measure light intensity

Question 19

How do greenhouses increase carbon dioxide concentration?

Answer 19

Adding sodium bicarbonate to the soil and pumping CO2 into greenhouse from tanks.

Question 20

How do greenhouses increase water?

Answer 20

Automated watering systems.

Question 21

During daylight plants produce more _____ by photosynthesis than they use up. At night plants only produce _____ ______ by respiration.

Answer 21

Oxygen

Carbon dioxide

Question 22

What is hydrogen carbonate indicator?

Answer 22

It used to measure carbon dioxide levels in aquatic systems.

Question 23

The indicator is ____ in equilibrium with the atmospheric air. It becomes _____/____ with increased carbon dioxide levels. It changes to ____ when carbon dioxide is removed.

Answer 23

Red
Orange/Yellow
Purple

Question 24

What does nitrogen help with in plants?

Answer 24

Growth of leaves and stems.

Question 25

What does phosphorus help in plants?

Answer 25

Healthy roots

Question 26

What does potassium help with in plants?

Answer 26

Healthy leaves and flowers