The immune system

The endocrine system produces hormones.

The pituitary gland is part of the endocrine system.

Where is the pituitary gland?

Tick (✓) one box.

In the head

In the heart

In the liver

Oestrogen is a hormone.

Which organ in the female reproductive system produces oestrogen?

Tick (✓) one box.

Kidney

Ovary

Stomach

Some chemicals in the environment affect the body in a similar way to hormones.

A scientist investigated the effect of feeding chemical X to rats.

Table 1 shows the results.

The scientist calculated the mean thickness of the uterus lining.

First, the scientist added together the measurements for all the rats in a group.

For the control group, the total was 4500 micrometres.

Calculate how many rats were in the control group.

Use Table 1.

Complete the sentence.

Choose the answer from the box.

The mean thickness of the uterus lining in the two groups in Table 1 was compared.

In rats fed chemical X, the mean thickness of the uterus lining

Some food packaging contains chemical Y.

Chemical Y decreases antibody production in humans.

Food packaging in landfill can release chemical Y into streams, rivers and lakes.

Which are two reasons why food packaging containing chemical Y is a problem?

Tick (✓) two boxes.

Chemical Y could become a fossil fuel.

Chemical Y could contaminate drinking water.

Chemical Y could get into food.

Chemical Y does not dissolve in water.

Chemical Y will be broken down quickly.

Which risk increases when a person produces fewer antibodies?

Tick (✓) one box.

Developing Type 1 diabetes

Getting lung cancer due to mutations

Not being able to recover from infections

If a pathogen enters the body, white blood cells can engulf and digest the pathogen.

What is the name of the process where white blood cells engulf and digest a pathogen?

The pathogen is digested by white blood cells.

Which of the following digests large molecules into smaller molecules?

Tick (✓) one box.

Carbohydrates

Enzymes

Lipids

Hormones affect the human body in many ways.

Figure 4 shows how the concentration of four female sex hormones changes during the menstrual cycle.

Explain how hormones X, Y and Z can be identified from Figure 4.

You should include the name of each hormone.

Endocrine disruptors are chemicals in the environment that affect the body in similar ways to hormones.

Chemical A is an endocrine disruptor.

Scientists investigated the effect of feeding chemical A to rats.

Table 4 shows the results.

Calculate the percentage increase in the mean thickness of uterus lining.

White blood cells produce antibodies.

Some endocrine disruptors decrease antibody production.

The human body should still produce antibodies many years after a vaccination.

Give one reason why it is important that the human body produces antibodies many years after a vaccination.

How do white blood cells reduce the symptoms of infectious diseases?

Tick (✓) one box.

By causing blood clotting

By decreasing phagocytosis

By destroying antiretroviral drugs

By producing antitoxins

The symptoms of a measles infection include: a fever

a red skin rash.

Why do antibiotics not treat measles?

Tick (✓) one box.

Antibiotics cause the measles pathogen to release toxins.

Antibiotics do not kill viruses.

Antibiotics increase body temperature.

Cilia are small hair-like structures in the trachea and bronchi.

Describe how mucus and cilia defend against the entry of pathogens into the lungs.

How does stomach acid defend the body against pathogens?

People can be vaccinated against measles.

What does the measles vaccine contain?

Tick (✓) one box.

Hormones

Two types of blood cell

Weakened pathogen

Which part of the blood produces antibodies after receiving the measles vaccination?

Tick (✓) one box.

Platelets

Red blood cells

White blood cells

Figure 5 shows how the concentration of measles antibodies in the blood changes after vaccination.

Complete Figure 5 to show how the concentration of measles antibodies will change after the exposure to measles pathogens.

In one group of people: 25 people have been vaccinated against measles

5 people have not been vaccinated against measles.

What is the simplest ratio of people who have been vaccinated to people who have not been vaccinated?

Tick (✓) one box.

30: 1

25: 1

5: 1

Scientists recommend that over 95% of the population should be vaccinated against measles.

What is the advantage of a large percentage of the population being vaccinated against measles?

The human immune system responds to pathogens entering the body.

Which part of the blood is responsible for an immune response?

Tick (✓) one box.

Platelets

Red blood cells

White blood cells

Some pathogens release toxins in the body.

Name the type of substance produced in the body that destroys the toxins.

Cells in the immune system engulf pathogens.

What is the name of this process?

Plants release pollen.

The human breathing system has defences against the entry of pollen and pathogens.

Draw one line from each adaptation of the breathing system to the description of that adaptation.

The immune response to pollen is an example of an allergy.

Suggest two symptoms of an allergy to pollen.

An allergy to pollen cannot be treated using antibiotics.

Suggest why.

Explain one problem caused by the overuse of antibiotics.

Figure 5 shows a diagram of blood.

Cells in the blood are specialised to have particular functions.

What process produces specialised cells?

Tick (✓) one box.

Draw one line from each blood component to a function of the component.

Some blood cells carry out phagocytosis.

What is phagocytosis?

Tick (✓) one box.

Cystic fibrosis is an inherited condition.

The allele for not having cystic fibrosis is dominant, R.

The recessive allele is r.

What term describes the genotype Rr ?

Tick (✓) one box.

Having symptoms of cystic fibrosis is a person’s phenotype.

What does the term ‘phenotype’ mean?

Tick (✓) one box.

Two people are planning to have a child.

Complete Figure 6 to show the possible genotypes of the child.

Draw a ring around one of the offspring in Figure 6 that would have cystic fibrosis.

What is the percentage chance of the child having cystic fibrosis?

Tick (✓) one box.

New drugs are being developed to treat the symptoms of cystic fibrosis.

Trials of new drugs are needed to work out the correct dose of the drug to use.

Give one other reason why drugs are trialled before they are used by patients.

Do not refer to dosage in your answer.

HIV infection can prevent the body’s immune system from destroying pathogens.

Explain the roles of white blood cells when a pathogen enters the body.

Name the type of drug that can be used to treat HIV.

Describe how AIDS is different from HIV infection.