Respiration

Pneumoconiosis is a lung disease caused by breathing in coal dust particles. The X-ray shows the lungs of a person with pneumoconiosis.

Coal dust particles collect in the alveoli and cannot be removed. Cells grow around these coal dust particles, forming tissue that traps the particles.

State what is meant by the term tissue.

Suggest why pneumoconiosis reduces the ability of a person to exercise.

In the UK, in 2013, breathing in dust particles resulted in diseases that caused 260 000 deaths. The graph shows the number of these deaths caused by breathing in dust particles of asbestos, coal and silica.

Calculate the number of deaths in the UK, in 2013, caused by breathing in dust particles other than asbestos, coal or silica.

number of deaths =_........

Give two conclusions that can be made from the data in the graph.

A student uses this apparatus to investigate the effect of nitrate ions on the growth of plants.

● A young plant is grown in a sterile solution containing all the mineral ions needed for growth.

● The student repeats the experiment with other young plants.

● The student also carries out the experiment with young plants grown in a sterile solution that contains all the mineral ions except nitrate.

● The student measures the length of the stem of each plant every five days. Some of the student’s results are shown in the table.

Describe the growth of the plants in each solution.

Explain why young plants absorb more mineral ions when air is bubbled through the solutions.

Suggest why each solution is sterilised at the start of this investigation.

Suggest why the glass jar is surrounded by cardboard during this investigation.

Identify the dependent variable in this investigation.

Name one biotic (living) variable that should be controlled in this investigation.

Chemotherapy is often used to help people with cancer. Chemotherapy kills cancer cells but may affect haemoglobin production in the body. A drug called EPO increases haemoglobin production in the body. Scientists investigated the effect of EPO on patients who had received chemotherapy. They injected EPO into these patients and blood samples were taken for several months to measure their haemoglobin levels. The table shows the results.

Plot a line graph to show the relationship between time and average haemoglobin level. Use a ruler to join the points with straight lines.

Name the dependent variable in this investigation.

Explain how the scientists made sure their results were reliable.

The scientists controlled biotic (living) factors so their results would be valid. Name two biotic factors that the scientists should have controlled.

Cancer patients often complain of tiredness after chemotherapy. Explain how EPO helps to reduce tiredness in these patients.

The scientists obtained blood samples using a needle attached to a syringe. Explain which type of blood vessel they should use to obtain the blood samples.

The table shows the concentration of sodium ions and chloride ions inside a plant root hair cell and in the water in the soil.

The ratio for the concentration of sodium ions in the root hair cell compared to the water in the soil is 71:1

Calculate the ratio for the concentration of chloride ions in the root hair cell compared to the water in the soil.

Adding too much water to soil will fill all the air spaces in the soil with water. Suggest why this will prevent root hair cells from absorbing sodium or chloride ions.

The table lists two other mineral ions. Complete the table by naming a molecule that is made in plants using the mineral ion.

(a) The diagram shows a human sperm, which is a specialised cell.

Suggest the function of each of the sections of the sperm cell.

head

middle piece

tail

The diagram shows a motor neurone, which is another specialised human cell.

Suggest two ways in which the structure of the motor neurone is adapted for its function.

The data shows the number of heart attacks in men and women of different ages from 1969 to 1998 in one area in England.

Plot a bar graph to show the data in the table.

Describe how the data differs for men and women.

Give an explanation for the change in the number of heart attacks from 1969 to 1998.

Explain why reducing the blood supply to the heart muscle cells can cause a heart attack.

The table shows the results of an investigation into the rate of sweating of a person when resting or running at different air temperatures.

Suggest why the investigation was carried out with the same person resting and running.

Compare the effect of increasing air temperature on sweat production when resting and when running.

Suggest why the rate of sweating changes when a person does exercise, such as running.

Suggest a method that you could use to measure the rate of sweating.

The photograph shows a bird called a parakeet.

Parakeets eat seeds. Parakeets can be eaten by birds of prey called raptors. Use this information to draw a food chain.

Many seeds contain starch. Suggest what happens to starch in the gut of a parakeet.

The graph shows the volume of oxygen used by a resting parakeet compared to a flying parakeet.

Calculate the extra volume of oxygen used in litres per gram per hour when flying compared to the volume used at rest. Show your working.

_........ litres per gram per hour

Like humans, parakeets need to keep their body temperature constant. Suggest how the volume of oxygen used by a parakeet at rest would change if it was moved to a colder environment.

The diagram shows a human sperm cell.

How many chromosomes are there in the nucleus?

Respiration takes place in the middle piece of the sperm cell. Explain why respiration is important to a sperm cell.

A sample of semen contains 40 million sperm cells. Only sixty percent of these sperm cells are capable of swimming. Calculate how many sperm cells in this semen sample are capable of swimming. Show your working.

Some men are infertile because they do not produce enough sperm cells or the sperm cells they produce are not good swimmers. There is a test that can be used to find out if a man is infertile. Semen is added to a solution in a test tube. The test tube is then sealed. The solution stays purple if oxygen is present and changes to pink if oxygen is absent. The diagram shows how the test works.

A man used this test and the solution remained purple. What does this suggest about the man’s sperm? Explain your answer.

Suggest two reasons why the results of the test might not be correct.

The diagram shows some of the blood vessels and a nephron in the human kidney. The numbers represent the concentration of glucose at various places in the blood vessels and in the nephron, in arbitrary units.

Explain how the structure of the blood vessels entering and leaving the glomerulus help to move glucose into the Bowman’s capsule.

What type of blood vessels are found in the glomerulus?

Describe how glucose is reabsorbed from the nephron back into the blood.

Suggest why glucose needs to be returned to the blood.

The diagram shows the apparatus used to investigate how quickly water passes through two different types of soil.

Each funnel contained 200 g of dry soil. Water was poured into each funnel to make the soil completely wet. Then 100 cm³ of water was poured on to the wet soil in each funnel and allowed to drain into the measuring cylinders. The volume of water collected in the cylinders was measured every two minutes until all 100 cm³ had been collected. The table shows the results.

Soil type is an independent variable in this investigation. What is meant by the term independent variable ?

What is the dependent variable in this investigation?

Tick the box to show the correct controlled variable in this investigation.

Calculate the average rate in cm³ per minute at which water drained through the clay soil. Show your working.

_........ cm³ per minute

The photographs show two stop clocks, A and B, that could be used to measure the time taken for water to drain through the soil in this investigation.

Which of these two stop clocks would give a more precise reading? Explain your answer.

Sandy soil contains large soil particles with big air spaces between them. Clay soil contains very small soil particles with small air spaces between them and most of these air spaces are filled with water.

Suggest why many plants may find it difficult to grow in sandy soil.

Use your knowledge of how plant roots absorb mineral ions to suggest why some plants may find it difficult to grow in clay soil.

The diagram shows the apparatus used in a seed germination experiment.

The two samples of seeds started at the same temperature of 18C. The diagram shows the temperature reading on each thermometer after 48 hours.

Complete the table to show the temperature of flask A and flask B.

Temperature in	C
Flask A	Flask B

Give a biological explanation for the difference in the temperature of flask A compared to flask B.

The seeds in both flasks were washed in disinfectant before being put into the flasks. Suggest why this was done.

The cotton wool kept the thermometers in place and prevented the seeds from falling out of the flasks. Suggest why cotton wool was used rather than a rubber bung.

The seeds used in the experiment were from the same species. Suggest one other variable that needs to be controlled in this experiment.