Blood

This question is about the human circulatory system.

Blood plasma transports blood cells around the body.

Give one other function of blood plasma.

Do not refer to oxygen in your answer.

Figure 5 shows a red blood cell.

The image of the red blood cell in Figure 5 is magnified 7200 times.

Calculate the real diameter of the red blood cell.

Give your answer in micrometres (µm).

Figure 6 shows the heart.

Blood pressure is a measure of the force of the blood against the walls of the blood vessels.

Table 5 shows information about the different types of blood vessel shown in Figure 6.

Complete Table 5 using the correct letters from Figure 6.

One row has been completed for you.

Name blood vessel D in Figure 6.

Describe the structure of the walls of an artery.

An athlete ran on a running machine.

The athlete:

• reached their maximum intensity of exercise and then stopped exercising

• had their use of oxygen recorded

• had the lactic acid concentration in their blood recorded.

During the exercise the athlete respired aerobically and anaerobically.

Explain why anaerobic respiration is less efficient than aerobic respiration.

Figure 7 shows the athlete’s use of oxygen and the lactic acid concentration of blood during exercise and after exercise.

Explain why the use of oxygen remained high after the athlete stopped exercising.

Some athletes regularly exercise in conditions that increase the number of red blood cells.

Explain why having an increased number of red blood cells is an advantage to an athlete.

Measles is caused by a virus.

The measles vaccine is given to children to prevent them becoming ill with measles.

Draw one line from each blood component to its function when someone is vaccinated against measles.

Blood component Function

Figure 3 shows information about trends in the UK for:

• percentage of children vaccinated

• the number of people with measles.

What year was the measles vaccine first used?

Use Figure 3.

Describe the trend in the number of people with measles from 1945 to 1975.

Use Figure 3.

In 1998, a scientific paper was published suggesting a link between condition X and one type of measles vaccine.

What happened to the percentage of children vaccinated against measles after the scientific paper was published in 1998?

Use Figure 3.

Why might the claims made in the scientific paper have affected the percentage of children vaccinated?

Tick () one box.

In 2010, the scientific paper linking condition X and the measles vaccine was shown to be based on false claims.

What should scientists do with scientific research to help detect false claims?

Tick () one box.

The person who wrote the scientific paper was paid to research the link between condition X and the measles vaccine.

Why are the claims in the scientific paper likely to be considered not valid?

Malaria is caused by a protist.

The protist is passed from one person to another person by mosquitos.

Which term describes the mosquito?

Tick (✓) one box.

The malarial protist is a eukaryotic cell.

Figure 2 shows a malarial protist.

Give two features of the malarial protist that show the cell is eukaryotic

and not prokaryotic.

Which organism is prokaryotic?

Tick (✓) one box.

The malarial protist reproduces asexually.

What is a feature of asexual reproduction?

Tick (✓) one box.

Mitosis occurs in the malarial protist during asexual reproduction.

The protist has 14 chromosomes.

How many chromosomes will each new protist cell have after mitosis?

Tick (✓) one box.

When a person has malaria, the protists destroy red blood cells.

What change would happen in the blood of a person with malaria?

Tick (✓) one box.

It is estimated that 210 million people are infected with malaria every year. Half of these infected people survive the disease.

Calculate how many people would survive the disease in 3 years if the estimate is correct.

Give your answer in standard form.

The spread of malaria can be controlled by using mosquito nets to avoid being bitten.

Describe two other ways that people can reduce the chance of being bitten by mosquitos.

Do not refer to mosquito nets in your answer.

Different types of disease may interact.

Scientists studied how having disorder S interacts with malaria.

The scientists calculated the chance of children with disorder S getting malaria.

Table 4 shows the results.

Describe the trend shown in Table 4.

Use data from Table 4.

The protist that causes malaria is passed from one person to another person by mosquitos.

What term describes an organism that passes a pathogen from one person to another person?

Figure 7 shows the malarial protist.

The malarial protist is a eukaryotic cell. Describe three ways the structure of the malarial protist is different from the structure of a prokaryotic cell. Do not refer to size in your answer.

During one stage of malaria infection, the malarial protists enter red blood cells and cause them to burst. Explain why the bursting of red blood cells causes tiredness.

The malarial protist reproduces sexually and asexually during a life cycle. Complete Table 3 to give three differences between sexual reproduction and asexual reproduction. One difference has been completed for you.

One drug for treating malaria prevents mitosis occurring in the malarial protist. The drug stops the synthesis of new DNA bases in the cell. Suggest how the drug prevents mitosis occurring.

Describe the process of cell division by mitosis.

Different types of disease may interact. Scientists studied the incidence of malaria infections in children:

• with disorder S

• without disorder S.

The incidence of malaria in children with disorder S was calculated as a percentage of the incidence in children without disorder S. Table 4 shows the results.

Describe what the results in Table 4 show about the interaction between disorder S and malaria.

A student prepared some animal cells to view using a microscope.

Figure 1 shows the student preparing the cells.

Name two pieces of laboratory equipment the student could have used to prepare cells to view using a microscope.

Figure 2 shows the student’s light microscope.

Name part A.

What is the function of part B ?

The student tried to look at the cells using the microscope.

Suggest one reason why the student could not see any cells when looking through part A.

Red blood cells are specialised animal cells.

Compare the structure of a red blood cell with the structure of a plant cell.

When placed into a beaker of water:

• a red blood cell bursts

• a plant cell does not burst.

Explain why the red blood cell bursts but the plant cell does not burst.

Figure 11 shows where three of the same type of tumour were found in a patient.

Malignant tumours are cancers.

Describe what happens to cells when a tumour forms.

What evidence is there in Figure 11 to suggest that the tumour in the lung is malignant?

Some types of cancer can cause the numbers of blood components in a person’s body to fall to a dangerously low level.

A person with one of these types of cancer may experience symptoms such as:

• tiredness

• frequent infections

• bleeding that will not stop after the skin is cut.

Explain how a very low number of blood components in the body can cause these symptoms.

Some patients with a very low number of blood cells may be given a blood

transfusion.

A blood transfusion is where a patient receives blood from a donor.

Different people have different blood groups.

Figure 12 shows:

• the red blood cells found in people with different blood groups

• the antibodies that can be made by people with different blood groups.

Antibodies can bind to antigens that have complementary shapes.

When antibodies bind to the antigens on red blood cells, many red blood cells begin to clump together.

Each red blood cell is about 8 µm in diameter.

Many capillaries have an internal diameter of about 10 µm.

In one type of blood transfusion, only red blood cells from a donor are transferred to

the patient.

It is dangerous for a patient with blood group A to receive red blood cells from a donor with blood group B.

Explain why.

Explain why blood group O red blood cells can be given to patients with any blood group.

Table 4 shows some of the risks associated with blood transfusions.

Which risk has the lowest probability of occurring?

Tick (✓) one box.

A person has a tumour blocking the tube leading from the gall bladder to the small intestine.

Explain why this person would have difficulty digesting fat.

Blood is transported around the body in blood vessels.

Draw one line from each type of blood vessel to the structure of the blood vessel.

Explain how the structure of an artery is related to its function.

Figure 9 shows blood viewed through a microscope.

Name A and B in Figure 9.

A red blood cell:

• has no nucleus

• contains a red pigment called haemoglobin.

Suggest how these adaptations help the red blood cell carry out its function.

The blood components are carried around the body in the liquid part of the blood. What is the liquid part of the blood called? Tick (✓) one box.

Table 2 shows the results of a man’s blood test.

Which component of the man’s blood is not within the normal range?

Suggest a symptom the man might show.

Figure 6 shows the internal structure of the human heart.

One of the heart valves is labelled.

Sometimes a valve in the heart can start to leak.

Explain why a person with a leaking heart valve has difficulty exercising.

A patient with a leaking heart valve may have the valve replaced.

A study compared two different types of replacement heart valve:

• mechanical valves

• biological valves from pigs.

The data used in the study was collected from female patients aged 50–69.

Table 4 shows the data.

Give one conclusion about the death of patients from heart-related problems after a valve replacement.

Include calculations to support your answer.

One risk of mechanical valves is that blood clots can form on the surface of the valve.

Name the component of the blood that starts the process of blood clotting.

Evaluate the use of mechanical replacement heart valves and biological replacement heart valves.

Use information from Table 4 and your own knowledge.

People with diabetes have difficulty controlling their blood glucose concentration.

Which part of the blood transports glucose?

Tick (✓) one box.

Glucose is often found in the urine of people with diabetes.

Name a chemical used to test for glucose.

Describe a test that could be used to show that a person’s urine contains glucose.

The body cells of a person with untreated diabetes lose more water than the body cells of a person who does not have diabetes.

Explain how diabetes can cause the body cells to lose more water.

Glucose is absorbed into the blood in the small intestine by both diffusion and active transport.

Describe how the small intestine is adapted for efficient absorption.

This question is about the circulatory system.

Draw one line from each blood component to its function.

Blood component
Function

Figure 6 shows cross sections of the three main types of blood vessel found in the human body. Each blood vessel is drawn to the scale shown.

Which blood vessel has the smallest diameter?

Tick one box.

Which blood vessel in Figure 6 is an artery?

Give one reason for your answer.

Table 1 gives information about the blood flow in two people.

Calculate the difference in blood flow between person A and person B.

Suggest why blood flow through the coronary arteries is lower in people with coronary heart disease.

Calculate the volume of blood flowing through the coronary arteries of person A in 1 hour.

Give your answer in dm³.

Coronary heart disease can be treated by:

• inserting a stent

using a Coronary Artery Bypass Graft (CABG).

Table 2 gives information about each method.

Give two advantages of using a stent instead of CABG.

Give two advantages of using CABG instead of a stent.

The circulatory system is composed of the blood, blood vessels and the heart.

Urea is transported in the blood plasma.

Name two other substances transported in the blood plasma.

Some athletes train at high altitude.

Training at high altitude increases the number of red blood cells per cm³ of blood.

Explain why having more red blood cells per cm³ of blood is an advantage to an athlete.

Which two blood vessels carry deoxygenated blood?

Tick two boxes.

Figure 4 shows the three types of blood vessel.

Which type of blood vessel carries blood into the right atrium?

Tick one box.

Compare the structure of an artery with the structure of a vein.

Heart rate is controlled by a group of cells. This group of cells act as a pacemaker.

Figure 5 shows a section through the heart.

Draw an X on Figure 5 to show the position of the pacemaker.

A patient may be fitted with an artificial pacemaker.

What condition may be treated using an artificial pacemaker?