The Rate of Photosythesis

Question 1

What provides the energy needed for photosynthesis?

Answer 1

Light

Light is essential for the process of photosynthesis in plants.

Question 2

What happens to the rate of photosynthesis as light intensity is increased?

Answer 2

Increases steadily up to a certain point

Beyond this point, other factors become limiting.

Question 3

What occurs when light intensity surpasses a certain level?

Answer 3

The rate will no longer increase

This is due to temperature or CO2 levels becoming the limiting factor.

Question 4

How can you change light intensity in a lab setting?

Answer 4

By moving a lamp closer to or further away from the plant

This allows for controlled experiments on photosynthesis.

Question 5

What shape does the graph take when plotting the rate of photosynthesis against lamp distance?

Answer 5

Weird-shaped graph

To obtain a clearer graph, measure light intensity or perform calculations.

Question 6

What is one of the raw materials needed for photosynthesis?

Answer 6

CO2

Carbon dioxide is crucial for the photosynthesis process.

Question 7

What happens to the rate of photosynthesis as the amount of CO2 increases?

Answer 7

Increases up to a point

After a certain level, CO2 is no longer the limiting factor.

Question 8

What must be true for light and CO2 for temperature to become the limiting factor?

Answer 8

They must be in plentiful supply

This suggests that both light and CO2 are sufficient for photosynthesis.

Question 9

What usually happens if temperature is the limiting factor?

Answer 9

It is too low

Enzymes required for photosynthesis work more slowly at low temperatures.

Question 10

What happens to enzymes if the plant gets too hot?

Answer 10

They will be damaged

High temperatures can destroy the enzymes needed for photosynthesis.

Question 11

At what temperature do enzymes start to get destroyed?

Answer 11

About 45 °C

This is considered high for outdoor conditions.

Question 12

What does the graph show regarding the rate of photosynthesis?

Answer 12

How the rate of photosynthesis is affected by light intensity and temperature

The graph illustrates the relationship between light intensity, temperature, and photosynthesis rates.

Question 13

What happens to the rate of photosynthesis as light intensity increases?

Answer 13

The rate of photosynthesis increases until it levels off

This leveling off indicates that another factor is limiting the rate.

Question 14

What effect does CO2 concentration have on the rate of photosynthesis?

Answer 14

Higher CO2 concentrations increase the rate of photosynthesis

This is shown by the line at 0.4% CO2 leveling off at a higher point than at 0.04% CO2.

Question 15

What does the leveling off of the lines at different CO2 concentrations indicate?

Answer 15

That CO2 concentration becomes a limiting factor

At 0.04% CO2, the concentration limits the rate of photosynthesis.

Question 16

True or False: Light intensity is the only factor affecting the rate of photosynthesis.

Answer 16

False

Both temperature and CO2 concentration also affect the rate.

Question 17

What happens to the light intensity as the distance from the lamp increases?

Answer 17

The light intensity decreases

This reflects the inverse proportionality between distance and light intensity.

Question 18

What is the relationship between distance and light intensity described in the text?

Answer 18

Inversely proportional

As distance increases, light intensity decreases.

Question 19

How does light intensity decrease according to the inverse square law?

Answer 19

In proportion to the square of the distance

This means that if the distance is doubled, the light intensity is reduced to a quarter.

Question 20

What happens to light intensity if the distance is halved?

Answer 20

Light intensity becomes four times greater

This illustrates the inverse square law.

Question 21

What happens to light intensity if the distance is tripled?

Answer 21

Light intensity becomes nine times smaller

This is a direct consequence of the inverse square law.

Question 22

What is the formula to calculate light intensity when using the inverse square law?

Answer 22

Light intensity = 1/d^2

‘d’ represents the distance from the light source.

Question 23

What is the light intensity when the lamp is 10 cm from the pondweed using the formula?

Answer 23

0.01 arbitrary units

This is calculated by substituting the distance into the formula.

Question 24

What is the most common method to artificially create the ideal environment for plants?

Answer 24

Growing them in a greenhouse

Greenhouses trap heat and help maintain optimal temperature.

Question 25

How do greenhouses help maintain temperature?

Answer 25

They trap the Sun's heat and may use heaters in winter ## Footnote Shades and ventilation can be used in summer to cool down.

Question 26

Why do commercial farmers supply artificial light after sunset?

Answer 26

To give plants more quality photosynthesis time ## Footnote This ensures optimal growth conditions.

Question 27

How can farmers increase carbon dioxide levels in a greenhouse?

Answer 27

By using a paraffin heater ## Footnote Burning paraffin produces carbon dioxide as a by-product.

Question 28

What is a benefit of keeping plants enclosed in a greenhouse?

Answer 28

Easier to keep them free from pests and diseases ## Footnote This helps maintain plant health.

Question 29

What can farmers add to the soil to promote healthy growth?

Answer 29

Fertilizers ## Footnote Fertilizers provide essential minerals for plants.

Question 30

What is the trade-off for farmers when creating ideal conditions for plants?

Answer 30

It costs money, but can lead to faster growth and more frequent harvesting ## Footnote Balancing the right amount of resources is crucial to avoid waste.

Question 31

Fill in the blank: The inverse square law states that light intensity is inversely proportional to the _______.

Answer 31

square of the distance ## Footnote This is key to understanding light intensity behavior.