Blood

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.

Figure 5 shows different parts of blood.

Which letter shows a white blood cell?

Tick (✓) one box.

Which part of the blood causes the blood to clot?

Tick (✓) one box.

Name two substances transported in the blood.

Healthy people can volunteer to donate blood.

The donated blood is then given to patients who need the blood.

When a volunteer donates blood:

• the volunteer’s health is checked

• a needle is used to remove blood from a vein in the arm

• the volunteer rests for 15 minutes after the donation.

Suggest one reason why blood is removed from a vein and not from an artery.

Patients may receive blood during a medical emergency.

Donating blood and receiving blood has risks.

Suggest one advantage and one disadvantage to a patient who receives blood.

Suggest one advantage and one disadvantage to the volunteer who donates blood.

Figure 6 shows a human heart.

The vena cava carries blood into the heart from the body.

Which blood vessel in Figure 6 is the vena cava?

Tick (✓) one box.

Which chamber of the heart pumps blood to the body?

Tick (✓) one box.

What is the name of the blood vessel that carries blood to the heart muscle?

Tick (✓) one box.

The heart and some blood vessels contain valves.

Which type of blood vessel has valves?

Tick (✓) one box.

What is the function of valves?

Figure 7 shows a blood capillary.

Explain one way the capillary is adapted for its function.

Table 2 shows information about the blood of four people.

Person W has 5 000 000 red blood cells in 1 mm³ of blood.

What is 5 000 000 written in standard form?

Tick (✓) one box.

Draw one line from each description to the person in Table 2 it describes.

Description
Person in Table 2

The greater the height above sea level, the less oxygen there is in the air.

People who live high above sea level have more red blood cells than people who live at sea level.

Some athletes train in mountains high above sea level.

Explain why having more red blood cells will improve an athlete’s performance.

Bacteria can cause a variety of diseases in humans.

What are two similarities between a bacterial cell and an animal cell?

Tick (✓) two boxes.

Salmonella food poisoning is caused by bacteria in food.

Give one symptom of salmonella food poisoning.

Do not refer to vomiting or diarrhoea in your answer.

What is the name of the first antibiotic developed?

A child with a severe bacterial infection was given a course of antibiotics.

Figure 7 shows how the concentration of live bacteria in the child’s body changed when taking the course of antibiotics.

The concentration of live bacteria in the body continued to increase after starting the course of antibiotics.

Suggest one reason why.

After 3 days of taking the antibiotic:

• the child felt better

• there were still bacteria in the child’s body.

Why did the child feel better?

Tick (✓) one box.

Suggest why doctors do not give antibiotics to patients with minor infections.

Figure 8 shows blood viewed using a microscope.

A vaccine will stimulate the production of antibodies.

Which part of the blood in Figure 8 produces antibodies?

Tick (✓) one box.

Which part of the blood in Figure 8 starts the clotting process?

Tick (✓) one box.

Bacteria can cause a variety of diseases in humans.

What are two similarities between a bacterial cell and an animal cell? Tick (✓) two boxes.

Salmonella food poisoning is caused by bacteria in food. Give one symptom of salmonella food poisoning. Do not refer to vomiting or diarrhoea in your answer.

What is the name of the first antibiotic developed?

A child with a severe bacterial infection was given a course of antibiotics.

Figure 1 shows how the concentration of live bacteria in the child’s body changed when taking the course of antibiotics.

The concentration of live bacteria in the body continued to increase after starting the course of antibiotics. Suggest one reason why.

After 3 days of taking the antibiotic:

• the child felt better

• there were still bacteria in the child’s body.

Why did the child feel better? Tick (✓) one box.

Suggest why doctors do not give antibiotics to patients with minor infections.

Figure 2 shows blood viewed using a microscope.

A vaccine will stimulate the production of antibodies. Which part of the blood in Figure 2 produces antibodies? Tick (✓) one box.

Which part of the blood in Figure 2 starts the clotting process? Tick (✓) one box.

A single-celled organism has a large surface area to volume ratio.

How does oxygen enter a single-celled organism?

Tick (✓) one box.

Figure 3 shows two cubes.

The surface area to volume ratio for cube A is 6:1

Calculate the surface area to volume ratio of cube B.

Surface area of one face of cube B

Total surface area of cube B

Volume of cube B

Multicellular organisms have exchange surfaces to absorb substances.

Figure 4 shows part of the exchange surface in the lungs.

Oxygen passes from the alveolus into the blood.

Name the part of the blood that carries the most oxygen.

Name the gas that passes out of the blood into the alveolus.

Alveoli provide a large surface area for gas exchange.

Give two other ways the lungs are adapted for efficient gas exchange.