Microscopy

Ciliated cells have small hair-like structures called cilia on the cell surface.

Ciliated cells are found in the trachea and in the oviducts.

Oviducts are part of the female reproductive system.

Figure 7 shows cilia lining an oviduct.

Give one piece of evidence that an electron microscope was used to produce the image shown in Figure 7.

Do not refer to colour in your answer.

Describe the function of ciliated cells in the oviduct.

The mean length of the cilia in an image was 6 mm.

The cilia were viewed at a magnification of 1.5 × 10³

Calculate the real mean length of the cilia.

Give your answer in micrometres (µm).

Red blood cells are a type of cell found in humans.

People with anaemia do not have enough red blood cells.

Explain why a person with anaemia is likely to experience muscle fatigue.

Scientists have produced red blood cells from stem cells in a laboratory.

The scientists:

• collected a sample of blood from a donor

• extracted 5 × 10⁵ stem cells from the sample.

Each stem cell was developed into 100 000 red blood cells.

35% of the red blood cells made from stem cells are suitable to use in a patient.

Calculate the number of red blood cells made from the donor’s sample that could be used in a patient.

Give your answer in standard form.

Patients with anaemia are sometimes given a blood transfusion.

A blood transfusion is when a patient is given blood.

The patient can be given red blood cells:

• produced from stem cells in a laboratory or

• from a whole blood donation.

Table 2 gives information about the two sources of red blood cells.

Evaluate the use of red blood cells:

• produced from stem cells in a laboratory

• from a whole blood donation.

You should refer to costs in your answer.

This question is about cells.

Figure 1 shows an animal cell.

Label parts A, B and C on Figure 1.

Choose answers from the box.

What is the function of the nucleus in a cell?

Tick (✓) one box.

What is the function of the mitochondria in a cell?

Tick (✓) one box.

Figure 2 shows a light microscope.

A student is given a prepared slide of animal cells to view using the microscope.

Complete the sentences.

Use labels from Figure 2.

Place the slide on the.

Use the objective lens that has low power.

Direct the light by moving the.

Make the image larger by using the high power

Figure 3 shows a different animal cell.

Calculate the magnification of the image in Figure 3.

Complete the following steps.

Measure the width of the image from Y to Z, in millimetres (mm).

Give the width of the image in micrometres (µm).

1 mm = 1000 μm

The cell in Figure 3 has a real width of 40 micrometres (μm).

Use the equation to calculate the magnification.

This question is about microscopy.

Figure 3 shows bacteria viewed using a microscope.

What type of microscope was used to view the bacteria in Figure 3 ?

Give a reason for your answer.

Type of microscope

Bacterial cells are prokaryotic cells.

Give three ways that a prokaryotic cell is different from a eukaryotic cell.

Figure 4 shows a special slide used to determine the size of a cell viewed using a microscope.

Calculate the magnification of the cell shown in Figure 4.

Figure 10 shows onion cells viewed using a light microscope.

Figure 11 shows the apparatus given to a student.

Describe how the student could use the apparatus to estimate the mean length of onion cells on the slide.

Figure 2 shows onion cells viewed using a light microscope.

Figure 3 shows the apparatus given to a student.

Describe how the student could use the apparatus to estimate the mean length of

onion cells on the slide.

Figure 2 shows a section through a leaf.

Give one way that the palisade layer is adapted for photosynthesis.

Gases pass into and out of the leaf through small pores in the surface of the leaf.

What are the small pores labelled X called?

Tick (✓) one box.

A student viewed a section of a leaf using a microscope.

The student measured the length of one of the palisade cells.

The cell image measured 28 mm in length when viewed at a magnification of ×400

Calculate the real length of the palisade cell in millimetres (mm).

Use the equation:

Convert the real length of the cell from millimetres to micrometres (µm).

1 mm = 1000 µm

Carbon dioxide can move into and out of cells.

What is the process by which carbon dioxide can move into and out of cells?

Tick (✓) one box.

Figure 3 shows a diagram of four cells.

Each cell is surrounded by carbon dioxide molecules.

Which cell will carbon dioxide move into at the fastest rate?

Give a reason for your answer.

Tick (✓) one box.

A student investigated the effect of different colours of light on the rate of photosynthesis.

Figure 4 shows some of the apparatus the student used.

The student placed the apparatus in blue light, then in green light and then in red light.

The student measured the rate of photosynthesis in each colour of light.

What two measurements should the student make to calculate the rate of photosynthesis?

Give two variables the student should keep the same in this investigation.

Table 2 shows the results.

Complete Figure 5.

You should:

• label the y-axis

• use a suitable scale

• plot the data from Table 2 as a bar chart

• label each bar.

Look at Table 2.

What colour of light should be used to grow plants in a greenhouse?

Tick (✓) one box.

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:

Pathogens are microorganisms that cause diseases. Gonorrhoea, malaria and measles are three diseases in humans.

Draw one line from each disease to the pathogen that causes the disease.

Malaria is transmitted by mosquitos. Male mosquitos can be sterilised so they are infertile. The spread of malaria is reduced by releasing sterile mosquitos into the environment. Explain how releasing sterile mosquitos reduces the spread of malaria.

Pathogens also cause diseases in plants. Figure 4 shows a rose black spot fungal spore and a tobacco mosaic virus.

Name the piece of equipment used to view the virus.

How many times longer is the fungal spore than the virus? Use Figure 4.

Explain why plants infected with tobacco mosaic virus grow slowly.

Starch is digested to form sugar molecules in the digestive system.

What is the name of the enzyme that digests starch?

Where are most food molecules absorbed? Tick (✓) one box.

Figure 6 shows two villi. Figure 6 also shows one cell on the surface of a villus as seen using an electron microscope.

Give one advantage of using an electron microscope compared with using a light microscope.

What type of blood vessel is labelled X ? Tick (✓) one box.

The real length of one villus is 0.8 mm Calculate the image length if the villus is viewed at a magnification of ×20 Use the equation:

Figure 7 shows two cells from the surface of a villus. There are sugar molecules inside and next to each cell.

Name the process by which sugar moves into cell A.

Name the process by which sugar moves into cell B.

Give one use of sugar in the body.

Figure 6 is repeated below.

Explain how villi are adapted for efficient absorption of sugar molecules.

Starch is digested to form sugar molecules in the digestive system.

What is the name of the enzyme that digests starch?

Where are most food molecules absorbed? Tick (✓) one box.

Figure 2 shows two villi. Figure 2 also shows one cell on the surface of a villus as seen using an electron microscope.

Give one advantage of using an electron microscope compared with using a light microscope.

What type of blood vessel is labelled X ? Tick (✓) one box.

The real length of one villus is 0.8 mm Calculate the image length if the villus is viewed at a magnification of ×20 Use the equation:

Figure 3 shows two cells from the surface of a villus. There are sugar molecules inside and next to each cell.

Name the process by which sugar moves into cell A.

Name the process by which sugar moves into cell B.

Give one use of sugar in the body.

Figure 2 is repeated below.

Explain how villi are adapted for efficient absorption of sugar molecules.

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.

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 cell structures.

Draw one line from each cell structure to the type of cell where the structure is found.

Type of cell where the Cell Structure structure is found

Figure 11 shows a plant cell.

What are the names of structures A, B and C ?

Tick one box.

A student observed slides of onion cells using a microscope.

Figure 12 shows two of the slides the student observed.

The cells on the slides are not clear to see.

Describe how the student should adjust the microscope to see the cells on Slide A more clearly.

Describe how the student should adjust the microscope to see the cells on Slide B more clearly.

The student made the necessary adjustments to get a clear image.

Figure 13 shows the student’s drawing of one of the cells.

The real length of the cell was 280 micrometres (µm).

Calculate the magnification of the drawing.

This question is about cell structures.

Draw one line from each cell structure to the type of cell where the structure is found. Type of cell where the Cell Structure structure is found

Figure 1 shows a plant cell.

What are the names of structures A, B and C ? Tick one box.

A student observed slides of onion cells using a microscope. Figure 2 shows two of the slides the student observed.

The cells on the slides are not clear to see.

Describe how the student should adjust the microscope to see the cells on Slide A more clearly.

Describe how the student should adjust the microscope to see the cells on Slide B more clearly.

The student made the necessary adjustments to get a clear image. Figure 3 shows the student’s drawing of one of the cells.

The real length of the cell was 280 micrometres (µm). Calculate the magnification of the drawing.