Photosynthesis

This question is about photosynthesis.

Complete the equation for photosynthesis.

Choose answers from the box.

What is the chemical formula for glucose?

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Give two ways plants use the glucose produced by photosynthesis.

A person has two greenhouses.

In each greenhouse, the plants:

• are all the same type

• receive the same intensity of light and the same volume of water

• grow in the same type of soil.

Figure 7 shows the greenhouses.

The person burns logs in the wood burner in greenhouse B.

Explain why the plants in greenhouse B grow faster than the plants in greenhouse A.

This question is about photosynthesis.

What is the symbol equation for photosynthesis?

Tick (✓) one box.

A student investigated the relationship between temperature and the rate

of photosynthesis.

The student measured the volume of gas produced by an aquatic plant in 1 hour.

The student collected the gas in a measuring cylinder.

Table 2 shows the results.

Describe the effect of increasing temperature on the rate of photosynthesis.

Use data from Table 2.

Explain why no gas was produced by the plant at 45 °C.

How could the student increase the accuracy of the results?

Tick (✓) one box.

A person grows tomatoes in a greenhouse.

The mean temperature of the greenhouse is 15 °C.

A heater would keep the temperature of the greenhouse at 25 °C.

Suggest two reasons against using a heater set at 25 °C in the greenhouse.

Do not refer to cost in your answer.

The person cut a stem from one of the tomato plants.

The cut stem was placed in soil to grow new roots.

Which tissue in the cut stem will differentiate into new root cells?

Tick (✓) one box.

Photosynthesis is an important chemical reaction in plants.

Why is light needed for photosynthesis?

What is the equation for photosynthesis? Tick (✓) one box.

A student investigated the effect of different colours of light on the rate of photosynthesis at room temperature. The student used pondweed in water. A piece of pondweed was placed in red light, then in blue light and then in green light. Each colour of light was the same intensity. Describe how the student should make accurate measurements to obtain valid results for the rate of photosynthesis.

A scientist investigated the effect of different wavelengths of light on the rate of photosynthesis. The wavelength of light determines the colour of the light. Figure 8 shows the student’s results. Figure 9 shows the scientist’s results.

Why are the results for the two investigations presented differently?

Suggest the range in wavelength of green light. Use Figure 8 and Figure 9.

Cells are the building blocks of life.

Draw one line from each type of organism to the diagram of one of its cells.

Type of organism
Diagram of one cell

Cells contain structures. These structures have different functions.

Draw one line from each function to the correct structure.

Chemicals are produced in cells.

Complete the sentences.

Choose answers from the box.

A chemical excreted by animals is.

A chemical stored in animal cells is.

A chemical stored in plant cells is.

A chemical that strengthens plant cell walls is

Figure 1 shows a diagram of muscle cells.

Give one function of muscle cells.

Explain how muscle cells are adapted for their function.

Use Figure 1.

One muscle cell was 0.05 mm wide.

When viewed using a microscope the image of the muscle cell was 2 mm wide.

Calculate the magnification used to view the cell.

Use the equation:

This question is about plant transport systems.

Which organ in a plant absorbs water from the soil?

The concentration of nitrate ions in the soil is lower than the concentration of nitrate ions inside a plant.

How would the nitrate ions move from the soil into the cells of this plant?

Tick (✓) one box.

Dissolved sugars are transported in the phloem.

What is the name of the process that moves dissolved sugars through the phloem?

Tick (✓) one box.

Give one use of sugars in a plant.

Stomata are openings on the surface of a leaf.

Stomata allow gases to move into and out of a leaf.

Figure 5 shows the surface of a leaf.

What is cell X ?

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Why do the stomata open during the day?

Tick (✓) one box.

The area of the leaf shown in Figure 5 is 0.25 mm².

Calculate the number of stomata per mm² for the leaf in Figure 5.

Use the equation:

A student investigated the number of stomata per mm² on the upper and lower

surfaces of leaves.

The leaves were taken from the same plant.

Table 1 shows the results.

Calculate mean value X in Table 1.

Water vapour is lost through stomata.

Explain the difference in the number of stomata on the upper and lower surfaces of the leaves.

Use Table 1.

Plants absorb light for photosynthesis.

Which is the equation for photosynthesis?

Tick (✓) one box.

A student investigated the effect of light intensity on the rate of photosynthesis.

Figure 6 shows the apparatus.

This is the method used.

1. Set up the apparatus as shown in Figure 6.

2. Place the pondweed 10 cm away from the lamp.

3. Switch on the lamp.

4. Record the number of bubbles of gas produced in 5 minutes.

5. Repeat steps 2 to 4 with the pondweed at different distances from the lamp.

What was the independent variable in this investigation?

Tick (✓) one box.

The lamp gets warm when it is on. This causes the temperature of the water

to increase.

Explain how an increase in temperature would affect the results of this investigation.

Suggest one way the investigation could be improved so the temperature of the water does not increase.

Suggest two improvements to the investigation so the results would be more valid.

Do not refer to controlling the temperature of the water.

Table 2 shows the results.

Calculate the rate of photosynthesis when the pondweed was 40 cm from the lamp.

Give the rate of photosynthesis as the number of bubbles of gas produced per minute.

Give one conclusion that can be made from Table 2.

Plot the data from Table 2 on Figure 7.

Draw a line of best fit.

Predict the number of bubbles that would be produced in 5 minutes if the pondweed was 60 cm from the lamp.

Use Figure 7.

Plants absorb light for photosynthesis.

Which is the equation for photosynthesis? Tick (✓) one box.

A student investigated the effect of light intensity on the rate of photosynthesis. Figure 1 shows the apparatus.

This is the method used.

1. Set up the apparatus as shown in Figure 1.

2. Place the pondweed 10 cm away from the lamp.

3. Switch on the lamp.

4. Record the number of bubbles of gas produced in 5 minutes.

5. Repeat steps 2 to 4 with the pondweed at different distances from the lamp.

What was the independent variable in this investigation? Tick (✓) one box.

The lamp gets warm when it is on. This causes the temperature of the water

to increase.

Explain how an increase in temperature would affect the results of this investigation.

Suggest one way the investigation could be improved so the temperature of the water does not increase.

Suggest two improvements to the investigation so the results would be more valid. Do not refer to controlling the temperature of the water.

Table 1 shows the results.

Calculate the rate of photosynthesis when the pondweed was 40 cm from the lamp. Give the rate of photosynthesis as the number of bubbles of gas produced per minute.

Give one conclusion that can be made from Table 1.

Plot the data from Table 1 on Figure 2. Draw a line of best fit.

Predict the number of bubbles that would be produced in 5 minutes if the pondweed was 60 cm from the lamp. Use Figure 2.

A student investigated the effect of light intensity on the rate of photosynthesis.

Figure 1 shows some of the apparatus used.

Name the gas produced by the pondweed in the light.

Describe one way the student could change the intensity of light reaching the pondweed.

Describe how the student could use the apparatus in Figure 1 to measure the rate of photosynthesis.

Figure 2 shows the student’s results.

What was the maximum rate of photosynthesis?

At which light intensity was light a limiting factor?

Tick (✓) one box.

Light intensity can affect the rate of photosynthesis.

Give one other factor that can affect the rate of photosynthesis.

Figure 8 shows a root hair viewed using a microscope.

The root hair was viewed at a magnification of ×50 The image length of the root hair X – Y is 43 mm Calculate the real length of the root hair in micrometres (µm).

A microscope has a ×5 eyepiece lens. Describe how to use this microscope to observe a prepared slide of root hair cells at a magnification of ×50

Root hair cells absorb water and mineral ions from the soil. A scientist investigated the rate of nitrate ion uptake by two seedlings. Figure 9 shows how the investigation was set up.

The scientist determined the mass of nitrate ions absorbed by each seedling every 30 minutes for 4 hours. Table 5 shows the results.

Describe the changes in the rate of absorption of nitrate ions for the seedling with no oxygen added. Use information from Table 5.

Explain what the results in Table 5 show about how nitrate ions are absorbed.

Nitrate ions are essential for plants to grow. Describe how nitrate ions are used in a plant to help the plant grow.

This question is about photosynthesis.

What are the two products of photosynthesis?

Tick two boxes.

A student investigated the effect of light intensity on the rate of photosynthesis.

Figure 4 shows the apparatus.

This is the method used.

1. Place the pondweed at 5 cm from the light source.

2. Measure the rate of photosynthesis by counting the number of bubbles produced in 30 seconds.

3. Repeat the investigation with the pondweed at different distances from the light source.

How could the student measure the rate of photosynthesis more accurately?

Tick two boxes.

The LED light source does not get hot.

Why is this important?

Table 1 shows the student’s results.

Calculate the number of bubbles produced in 2 minutes when the light source was 10 cm from the pondweed.

Plot the data from Table 1 on Figure 5

Draw a line of best fit.

Give one conclusion that can be made from these results.

This question is about photosynthesis.

What is the correct balanced equation for photosynthesis? Tick one box.

What type of reaction is photosynthesis? Tick one box.

A student investigated the effect of light intensity on the rate of photosynthesis. Figure 5 shows the apparatus used.

Sodium hydrogencarbonate solution releases carbon dioxide gas for the pondweed. This is the method used.

1. Place the pondweed at 5 cm from the light source.

2. Measure the rate of photosynthesis by counting the number of bubbles produced in 1 minute.

3. Repeat with the pondweed at 10 cm and at 20 cm from the light source.

Counting the number of bubbles produced in 1 minute is not an accurate way to measure the rate of photosynthesis. Suggest two ways the method could be improved to measure the rate of photosynthesis more accurately.

The LED light source does not get hot. Explain why it is important that the pondweed remains at a constant temperature.

Light intensity can be calculated using the inverse square law:

Where I is light intensity and d is the distance of the pondweed from the light source. The student placed the pondweed at 5, 10 and 20 cm from the light source. Explain how light intensity changes as the distance of the pondweed from the light source is doubled. You must include calculations in your answer.

The student’s results are shown in Table 1

Predict how many bubbles of gas would be produced in 1 minute if the pondweed was placed 40 cm from the light source. Give a reason for your prediction.

Describe how the student could change the method to investigate the effect of carbon dioxide concentration on the rate of photosynthesis. You should include:

• how to change the independent variable

• two control variables.

Use Figure 5 on page 9 to help you answer this question.