OCR GCSE Biology B (21st Century) Depth in Biology Higher June 2022 question paper J257/04

The pupil of the human eye changes size in different light levels.

A diagram of the eye is shown in Fig. 1.1.

Which structure in the eye changes the size of the pupil?

Tick (✓) one box.

The pupil changing size is a reflex action that happens in response to light. It uses a reflex arc in the nervous system.

The pupil reflex arc includes a sensory neuron that connects the eye to the spinal cord.

State two other types of neurons that must be part of the pupil reflex arc.

Ali plans to investigate the effect of light brightness on the diameter of the pupil of a person’s eye.

The method Ali plans to use is shown in Fig. 1.2.

1. Shine a bright light into the person’s eye.

2. Hold a ruler up to their eye and measure the diameter of the pupil.

3. Repeat with light at a different brightness.

Fig. 1.2

Ali’s teacher says that Ali’s method is not safe and could damage the person’s eye.

Identify the structure in the person’s eye that could be damaged by step 1, and suggest why the damage would affect the person’s vision.

Structure that could be damaged........

Why this would affect the person’s vision........

Identify the structure in the person’s eye that could be damaged by step 2, and suggest why the damage would affect the person’s vision.

Structure that could be damaged........

Why this would affect the person’s vision........

What was the diameter of the person’s pupil in complete darkness?

What would you conclude is the smallest possible diameter of the person’s pupil?

Explain your answer.

Calculate the rate at which the pupil diameter changed between 25% and 50% light brightness.

Rate =........ mm / %

* Describe a method that can be used to collect the data shown in Fig. 1.3. Assume that 100% light brightness is a normally lit room.

In your answer you should describe:

• how you would safely change the light brightness and measure the results

• things you would do or control to make sure the measurements are as accurate as possible.

Elysia sea slugs are very unusual animals.

The sea slugs eat algae. The slugs take chloroplasts from the algae cells. The chloroplasts stay inside the slugs and continue to work.

Suggest why it is an advantage to a sea slug to have working chloroplasts in its body.

When a sea slug’s body is attacked by predators, its head can separate from the body.

The head continues to live and grows a new body. All of the different tissues and organs for the slug’s new body grow from a particular type of cell.

Explain how these cells make tissues and organs for the slug’s new body.

Gentoo penguins live on islands near South America.

The number of Gentoo penguins on the islands is decreasing.

Suggest one factor that could have caused the decrease in the number of Gentoo penguins.

Scientists used to think all the Gentoo penguins were the same species.

New evidence suggests that there are four different species of Gentoo penguins.

Describe evidence that scientists could have collected from the penguins’ cells to show that there are four different species.

The diagram shows a cell from a Gentoo penguin.

The presence of mitochondria shows that this is a eukaryotic cell.

Which other structure shows that this is a eukaryotic cell?

Tick (✓) one box.

If a cell contains a vacuole, this suggests it could be a plant cell.

State one other structure that suggests a cell is a plant cell.

The length of a cell is 0.00002 m.

How is the length of the cell written in standard form?

2 × 10^–5 m 2 × 10^–4 m 2 × 10⁴ m 2 × 10⁵ m

The length of a mitochondrion is 3 10^–6 m.

What is another way to write the length of the mitochondrion?

0.0003 m
0.00003 m
0.000003 m
0.0000003 m

Bacteria can become resistant to antibiotics.

In the Petri dish containing antibiotic B, the bacterial culture has a radius (r) of 5 mm.

Calculate the area of the bacterial culture in this Petri dish.

Use the equation: area = 3.14 × r²

Which antibiotic would be the best choice to treat a sick patient who was infected with this type of bacteria?

Describe the evidence in Fig. 4.1 that supports your choice.

Antibiotic........

Evidence........

Fig. 4.2 shows the number of infections (rounded to the nearest 100) with antibiotic-resistant bacteria in England over four years.

Calculate the percentage increase in the number of infections with antibiotic-resistant bacteria from 2017 to 2018.

Give your answer to 1 significant figure.

Predict what the number of infections with antibiotic-resistant bacteria might have been in 2019.

Explain your answer.

Prediction........

Explanation........

A bacterium can become resistant to an antibiotic if it receives a plasmid from another bacterium.

Explain what a plasmid is.

Explain how receiving a plasmid causes a bacterium to become resistant to an antibiotic.

Explain how a bacterium could become resistant to an antibiotic without receiving a plasmid.

Photosynthesis takes place in plants.

Starch is a carbohydrate that is made when a plant photosynthesises.

Sam investigates the effects of different conditions on the presence of starch in three plant shoots. All three plants are given plenty of water throughout the experiment.

The method Sam uses for the experiment is shown in Fig. 5.1.

1. Keep three plant shoots in a dark place for two days.

2. Test 1: Cut a small piece of leaf tissue from each plant A, B and C. Test the pieces of leaf tissue for starch.

3. Wrap the leaf of plant B in metal foil.

4. Put the leaf of plant C inside an open conical flask containing potassium hydroxide solution to absorb carbon dioxide.

5. Keep the three plant shoots in bright light for one day.

6. Test 2: Cut a small piece of leaf tissue from each plant. Test the pieces of leaf tissue for starch.

Fig. 5.1

Fig. 5.2 shows the plants during step 5 of Sam’s method.

Some of Sam’s results are shown in Table 5.1.

State the name of the reagent used to test for starch.

Describe a conclusion that can be made from the result of test 2 for plant B.

Predict the result of test 2 for plant A.

Explain your prediction.

Prediction........

Explanation........

Stores of starch can be broken down to make glucose.

Suggest how this helps to explain the result of test 1 for plant A.

Suggest why it is helpful to keep the three plants in the dark for two days at the start of the experiment (step 1).

Sam predicts that test 2 for plant C would show no starch was present. However, the test shows that starch is present.

Describe and explain one improvement to their method that would produce the result Sam predicted for test 2 for plant C.

A tank of water containing living pondweed is placed next to the window. Pondweed is a plant that lives in water.

Fig. 5.3 shows how the amounts of oxygen and carbon dioxide in the water changes over 24 hours.

Five time points in Fig. 5.3 have been labelled A, B, C, D and E.

At which time point were the concentrations of oxygen and carbon dioxide exactly the same?

Between which two time points is the line for oxygen represented by the equation y = mx + c?

Time points........ and........

* A student concludes that time point D is sunset.

Describe and explain how Fig. 5.3 supports the student’s conclusion.

Plants that grow in soil absorb water and nitrate ions through their roots.

Two cells from the outside edge of a root are shown in the diagram.

Which statement explains why the cell membrane of the root hair cell is described as “partially permeable”?

Tick (✓) one box.

Explain how water molecules are absorbed into the root hair cell from wet soil.

Explain how nitrate ions are absorbed into the root hair cell from the soil.

Explain why the structure of cell A means it is better than cell B at absorbing substances from the soil.

Scientists are developing new vaccines against human diseases such as influenza.

New vaccines must be tested before they can be approved for widespread use in the population.

New vaccines are tested in pre-clinical trials before they are tested in humans.

Describe two ways in which a new influenza vaccine could be tested in pre-clinical trials.

The next stage of testing involves clinical trials in human volunteers.

A new medicine is usually tested in two groups of people. First, it is tested in:

• Group 1: Healthy people who do not have the disease.

Then it is tested in:

• Group 2: People who have the disease.

Suggest why a new vaccine is tested in group 1 but not in group 2.

One new type of vaccine against influenza is made of mRNA. The vaccine contains mRNA taken from the influenza virus.

• When a person is vaccinated, influenza mRNA from the vaccine enters some of the person’s cells.

• These cells use the mRNA to make influenza protein.

Describe how the person’s cells will use the influenza mRNA to make influenza protein.

Explain how the person’s body will react to the influenza protein and how this could protect them from catching influenza in the future.