Preventing, Treating & Curing Diseases (AQA GCSE Combined Science: Synergy: Life & Environmental Sciences): Exam Questions

Chlamydia, HIV and human papillomavirus (HPV) are sexually transmitted diseases (STDs).

Which other disease is sexually transmitted?

The human immune system responds to pathogens entering the body.

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

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.

New cells are produced during the formation of an embryo.

Figure 14 shows how a human baby is formed.

Complete the sentences about the processes shown in Figure 14.

Choose answers from the box.

The egg cell and the sperm cell fuse together during ___________.

Stem cells are produced when the newly formed cell divides by ___________ .

Stem cells become specialised cells during the process of ___________ .

Some people believe using embryonic stem cells in medical research is unethical.

Give one reason why.

Scientists tested a new drug to treat tumours in mice.

All the mice had the same type of tumour.

This is the method used.

1. Inject six mice with the drug once a day for 24 days.

2. Measure the volume of the tumour every 4 days.

3. Repeat steps 1 and 2, injecting a new group of mice with the drug twice a day.

Figure 15 shows the results.

Six other mice were given an injection that did not contain the drug.

Why did the scientists use mice that were not given the drug?

Describe how the drug injected once a day and the drug injected twice a day affected the volume of the tumour.

Use data from Figure 15.

Organisms have been genetically modified (GM) for many reasons.

What has been genetically modified to produce a hormone that reduces blood glucose concentration?

Scientists are researching the production of GM pigs.

Organs from GM pigs could be transplanted into humans.

What is one advantage of using organs from GM pigs instead of using organs from human donors?

Describe how a human gene could be used to genetically modify a pig embryo.

This question is about health.

Some pathogens cause food poisoning.

Explain how the stomach is adapted to prevent food poisoning.

Different types of disease may interact.

Suggest one type of disease that may be triggered by infection with human papillomavirus (HPV).

Chlamydia, HIV and HPV are sexually transmitted diseases (STDs).

Chlamydia is caused by the same type of microorganism as gonorrhoea.

Suggest how chlamydia infections are treated.

Students were asked to estimate the percentage risk of a person becoming infected with different STDs.

The estimate was compared to the actual percentage risk of infection.

Figure 8 shows the results.

Why is the data in Figure 8 plotted as a bar chart and not as a line graph?

The difference between the estimated risk and the actual risk is not the same for each STD.

Suggest two reasons why.

Explain why patients with late-stage HIV infection or AIDS are likely to become very ill from other infections.

A tumour is a group of abnormal cells that form a lump.

Give one factor that causes cells to form tumours.

Tumours can be benign or malignant.

Malignant tumours are cancers.

Give two ways a malignant tumour is different from a benign tumour.

Scientists tested a new drug to treat tumours in mice.

All the mice:

• had the same type of tumour

• were the same age

• were female.

This is the method used.

1. Inject the mice with a dose of 0.015 mg of the drug every day for 20 days.

2. Measure the volume of the tumour every 4 days.

3. Repeat steps 1 and 2 with new groups of mice using doses of:

• 0.030 mg of the drug

• 0.060 mg of the drug.

Give two control variables the scientists should have used in the drug test.

Do not refer to the type of tumour, the age of the mice or the sex of the mice.

Some mice were used as a control group.

Suggest what treatment was given to the control group.

[1 mark]

Give one reason why the scientists used a control group.

Figure 5 shows the results.

Calculate the percentage increase in the volume of the tumour in the control group between 0 and 20 days.

Give two conclusions about the effectiveness of the different doses of the drug.

Use Figure 5.

Suggest why the scientists measured the volume of the tumour instead of measuring the width of the tumour.

The scientists tested the drug in two stages:

• stage 1: drug tested on pieces of tumour tissue

• stage 2: drug tested on mice with tumours.

What extra information will the scientists gain by testing the drug on mice at stage 2?

Some mosquitos can transmit malaria.

Describe how a mosquito transmits malaria.

The human body protects itself from pathogens.

Describe how the skin and the stomach protect the human body from pathogens.

Earwax is produced by specialised skin cells in the ear.

Suggest one advantage of producing earwax.

The symptoms of a measles infection include:

• a fever

• a red skin rash.

Why do antibiotics not treat measles?

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.

Mucus__________________________________________________

Cilia____________________________________________________

How does stomach acid defend the body against pathogens?

People can be vaccinated against measles.

What does the measles vaccine contain?

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

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?

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 protein from the spider allows heart muscle tissues to function in low concentrations of oxygen.

Complete Table 4 to show the risks and benefits of the new drug.

Tick (✓) one box in each row.

Table 4

The drug made from the protein would be tested in a drug trial.

Part of the drug trial would involve a placebo.

Explain why a placebo is used in a drug trial.

The results of drug trials are peer reviewed.

Which are two advantages of peer review?

Tick (✓) two boxes.

The symptoms of a measles infection are:

• a fever

• a red skin rash.

Why can measles not be treated with antibiotics?

Describe two ways the human body defends against the entry of the measles pathogen into the lungs.

How do white blood cells respond to a vaccination against measles?

In the UK, most people have been vaccinated against measles.

In a sample population, the ratio of vaccinated people to unvaccinated people is: 594 000 : 99 000

Give 594 000 : 99 000 as the simplest whole number ratio.

Simplest whole number ratio = ______: ______

Explain why it is important that the ratio of vaccinated people to unvaccinated people is high.

Suggest what type of cell has the CCR5 protein in its cell membrane.

What type of drug is used to treat HIV?

Pathogens are microorganisms that cause infectious disease.

Draw one line from each disease to the way the disease is spread.

One way the human body protects itself against the entry of pathogens is by producing antimicrobial chemicals.

Antimicrobial chemicals kill pathogens.

Give two other ways the human body protects itself against the entry of pathogens.

Measles is a childhood disease caused by a microorganism.

Measles is not treated by antibiotics.

Give the reason why.

Vaccinations help people become immune to infections.

In 2013, 92% of children in the UK had two vaccination injections against measles.

Figure 6 shows how the concentration of antibodies in the blood changes after each measles vaccination.

Suggest what day the second vaccination was given.

What is the highest concentration of antibodies produced by the first vaccination?

How will the number of children getting measles change as more children are vaccinated against measles?

Give a reason for your answer.

Change: ________________________________________________

Reason: _________________________________________________

Statins are drugs used to treat coronary heart disease (CHD).

New drugs must be trialled before they can be licensed for use.

Some scientists trialled two different types of statin.

The scientists:

• conducted the trial on 325 patients with a history of CHD in their family

• used a double-blind trial method

• measured the change in blood cholesterol levels over two years

• measured the change in thickness of an artery wall over two years.

During the trials the statins are tested for side effects.

Give two other reasons why the statins are trialled before use.

Describe how the double-blind method is used in this trial.

The results of drug trials are peer reviewed before they are published.

Why are peer reviews important in drug trials?

Tick one box.

Table 2 shows the results of the trial.

Table 2

Drug A is more effective than Drug B.

Give two reasons that support this conclusion.

Use information from Table 2.

A scientist concludes that Drug A is a safer drug than Drug B.

Give two reasons why this is not a valid conclusion.

Bacteria can cause disease.

Figure 9 shows some features of a Salmonella bacterium

Draw one line from each feature of the Salmonella bacterium to the function.

How is Salmonella spread between people?

Tick one box.

Give two ways you could stop Salmonella from spreading.

Harmful bacteria can also be useful. Scientists are doing research to find out if Salmonella can be used in a vaccine to treat cancer.

The Salmonella vaccine can be injected into the blood or swallowed in a tablet.

One benefit of injecting the vaccine is that it gets to the cancer quickly in the blood.

What is another benefit?

Tick one box.

The Salmonella bacterium used in the vaccine is genetically modified using part of a virus.

Look at Figure 10.

Complete the sentences. Use the letters from Figure 10.

Bacteria reproduce quickly in part ____________ .

DNA with the desired gene is removed from the virus in part ________.

The chosen gene is inserted into the plasmid in part ____________.