Transport in plants

This question is about plants.

Some plants can respire anaerobically.

Which are the two products of anaerobic respiration in plants?

Tick () two boxes.

Figure 6 shows the structure of part of a leaf

What is the name of tissue A ?

Explain how tissue A is adapted to its function.

Plants absorb water from the soil.

Describe how water is transported from the soil through plant tissues to the atmosphere.

A student investigated the loss of mass from leaves that were placed in winds of different speed.

The student used an electric fan to create different wind speeds.

Figure 4 shows the apparatus.

This is the method used.

1. Record the mass of one leaf taken from a plant.

2. Attach the leaf to a stand.

3. Leave for 1 hour with the fan off.

4. Record the final mass of the leaf.

5. Repeat steps 1 to 4 with the fan set at different speeds. Use leaves of a similar size each time.

6. Calculate the loss of mass for each leaf.

Table 1 shows the results.

Why did the student do one experiment with the fan off?

How does increasing fan speed affect the loss of mass from the leaves?

Use Table 1.

Explain why the mass of the leaves decreased at all fan speeds.

The student repeated the investigation in a room at a higher temperature.

Complete the sentence.

Choose the answer from the box.

At a higher temperature the loss of mass from the leaves

would be.

How could the student check the repeatability of the results?

Tick (✓) one box.

Plants need water for photosynthesis.

Where do plants obtain water for photosynthesis from?

Plants lose water from their leaves through small pores called stomata.

What is the evaporation of water from leaves called?

Tick (✓) one box.

A student investigated the mass of water lost from a plant.

Figure 4 shows the apparatus.

This is the method used.

1. Seal a plastic bag around the pot of a potted plant.

2. Place the plant on a balance in a room at 20 °C.

3. Record the mass.

4. Record the mass every hour for 5 hours.

5. Calculate the total mass of water lost from the plant after each hour.

Table 1 shows the results.

Calculate mass X in Table 1.

Figure 5 shows the results.

What was the rate of water loss from the plant?

Tick (✓) one box.

The investigation was repeated at a lower temperature.

Draw one line on Figure 5 to show how the results would be different at a lower temperature.

Suggest one change to the investigation that would increase the rate of water loss from the plant.

Do not refer to temperature in your answer.

A leaf is a plant organ.

Figure 4 shows tissues in a leaf.

Which tissue is the epidermis?

Tick (✓) one box.

Explain how the spongy mesophyll is adapted for its function.

Use Figure 4.

The xylem is adapted to transport water through a plant.

Explain one way that xylem is adapted for its function.

Figure 5 shows a pair of guard cells around a stoma.

During the day, glucose is made in the guard cells.

Describe how an increase in glucose concentration in the guard cells causes the stoma to open.

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 ?

Tick (✓) one box.

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.

This question is about plant transport systems.

Describe how water is transported from the soil to the atmosphere through a plant.

Dissolved sugars are moved through a plant in phloem tissue. What is the name of the process that moves dissolved sugars through phloem tissue?

Phloem tissue is made of sieve tube cells and companion cells. Figure 6 shows a section of phloem tissue.

Explain one way sieve tube cells are specialised for their function. Use Figure 6.

What does the structure of the companion cells suggest about the process that moves dissolved sugars through the phloem tissue? Give a reason for your answer. Use Figure 6.

Describe why it is important that dissolved sugars are moved both upwards and downwards in a plant.

Water is lost from the leaves of plants through pores called stomata.

What is the loss of water from a leaf called? Tick (✓) one box.

Which cells control the size of stomata? Tick (✓) one box.

A student investigated the water loss when different surfaces of leaves were covered in grease. The grease blocks the stomata.

This is the method used.

1. Remove four similar leaves from one plant.

2. Put grease on different surfaces of the leaves as shown in Figure 4.

3. Record the mass of each leaf and attach the four leaves to a string.

4. After 24 hours record the mass of each leaf again.

Table 2 shows the results.

Calculate value X in Table 2.

The loss in mass of water was measured after 24 hours. Calculate the mass of water lost in grams per hour for leaf D.

The student concluded: ‘More water is lost from the lower surface of a leaf than from the upper surface.’

What evidence is there in Table 2 to support the student’s conclusion?

What do the results in Table 2 show about the number of stomata on the surfaces of a leaf? Tick (✓) one box.

The investigation was done at 20 °C How would the mass of water lost be different if the investigation was done at 25 °C? Give a reason for your answer.

This question is about organisation in living organisms.

Write the biological structures from the box in the correct size order.

Name one animal organ.

Which is a plant tissue?

Tick (✓) one box.

Figure 5 shows part of a root viewed using a microscope.

Figure 5

This image cannot be reproduced here due to third-party copyright restrictions

Explain how a root hair cell is specialised for its function.

Figure 6 shows a microscope.

It is easier to view the cells using the low power objective lens first.

Give one reason why.

To focus the image the objective lens should be moved away from the stage.

Give one reason why the objective lens should not be moved towards the stage.

The image of the prepared slide in Figure 6 is viewed with the ×10 objective lens.

The total magnification is ×50

What was the power of the eyepiece lens used?

Root hair cells do not contain chloroplasts.

Suggest one reason why.

Water is lost from the leaves of a plant through stomata.

What is the process by which water is lost from the leaves of a plant?

Tick (✓) one box.

Figure 7 shows stomata on the lower surface of a leaf.

What is the name of cell X ?

Tick (✓) one box.

The length of cell X is 25 mm when viewed at a magnification of ×800

Calculate the real length of cell X.

Give your answer in micrometres (µm).

1 mm = 1000 µm

Use the equation:

A student measured the mass of water lost from some similar plants. The plants were at different temperatures.

Figure 8 shows the apparatus used.

This is the method used.

1. Seal a plastic bag around the pot of a potted plant.

2. Place the potted plant with the bag on a balance in a room at 20 °C

3. Record the mass.

4. After 3 hours record the mass again.

5. Calculate the mass of water lost from the plant.

6. Repeat steps 1–5 at 25 °C and at 30 °C with other similar plants.

What was the independent variable in this investigation?

Tick (✓) one box.

Suggest why the student sealed a plastic bag around the pot.

Table 1 shows the student’s results.

What is the resolution of the balance used in this investigation?

Tick one box.

Calculate value X in Table 1.

Give one conclusion that can be made from the results in Table 1.

Give two factors that might affect the rate of water loss from the leaves.

Do not refer to temperature in your answer.

A student used a potometer to investigate the rate of water uptake in a plant shoot. Figure 3 shows a potometer.

As the shoot takes in water the air bubble moves. The rate of water uptake is the distance the air bubble moves in a given time. This is the method used.

1. Place the potometer in moist air at 25 °C

2. Position the air bubble at 0 mm in the capillary tube.

3. Record the position of the air bubble in the capillary tube every minute for 5 minutes.

4. Repeat steps 2 and 3 with the potometer in different conditions.

Table 3 shows the conditions used.

After investigation A the air bubble had moved part way along the capillary tube. Suggest how the student moved the air bubble back to 0 mm for the start of investigation B.

Capillary tubing is very narrow. Explain why narrow tubing was used.

Figure 4 shows the results for investigation A.

The cross-sectional area of the capillary tube was 0.8 mm² Calculate the rate of water uptake for investigation A in mm³/min

Table 4 shows the results from investigation B.

Plot the data from Table 4 on Figure 4. You should:

• draw a line of best fit

• label the line B.

Investigation C was carried out in dry air at 25 °C Draw a line on Figure 4 to show the results you would expect for investigation C. Label the line C.

The investigations were carried out in daylight. The air bubble would not move if the investigations were done in the dark. Explain why.

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.

A student investigated the effect of different concentrations of sugar solution on pieces of potato.

This is the method used.

1. Cut three pieces of potato to the same length.

2. Dry each piece on a paper towel.

3. Weigh each piece.

4. Place each piece in a different concentration of sugar solution.

5. Leave all three pieces for 2 hours.

6. Remove the three pieces of potato from the solutions.

7. Dry each piece on a paper towel.

8. Measure the length and mass of each piece of potato.

Figure 6 shows how the investigation was set up.

Why did the student dry each piece of potato before weighing it?

What two changes would you expect in the potato in tube A after 2 hours?

Tick two boxes.

Complete the sentences.

than the solution inside the potato cells.

The potato in tube B did not change.

Give one conclusion that can be made from this observation.

Figure 7 shows the root of a germinating seed.

Describe two ways the root is adapted to absorb water efficiently.