Communicable disease

Measles is an infectious disease caused by a pathogen.

What type of pathogen causes measles?

Give one way measles is spread from one person to another person.

One symptom of measles is pain.

In adults, aspirin can be used to treat the pain.

Which plant did aspirin originate from?

Give one other symptom of measles.

Do not refer to pain in your answer.

The spread of measles can be reduced by vaccination.

Explain why vaccinating large numbers of children helps to reduce the spread of the measles pathogen in the population.

Figure 9 shows information about the severity of measles infection in vaccinated and unvaccinated children.

There were 240 children in the survey.

Calculate how many unvaccinated children had a severe measles infection.

Use Figure 9.

It is recommended that all children are given a measles vaccination.

Give evidence from Figure 9 to support the recommendation.

Include data from Figure 9 in your answer.

Measles is an infectious disease caused by a pathogen.

What type of pathogen causes measles?

Give one way measles is spread from one person to another person.

One symptom of measles is pain.

In adults, aspirin can be used to treat the pain.

Which plant did aspirin originate from?

Give one other symptom of measles.

Do not refer to pain in your answer.

The spread of measles can be reduced by vaccination.

Explain why vaccinating large numbers of children helps to reduce the spread of the measles pathogen in the population.

Figure 1 shows information about the severity of measles infection in vaccinated and unvaccinated children.

There were 240 children in the survey.

Calculate how many unvaccinated children had a severe measles infection.

Use Figure 1.

It is recommended that all children are given a measles vaccination.

Give evidence from Figure 1 to support the recommendation.

Include data from Figure 1 in your answer.

A student investigated the effect of temperature on the rate of photosynthesis in pondweed.

Figure 4 shows how the student set up the apparatus.

This is the method used.

1. Prepare five tubes of pondweed as shown in Figure 4.

2. Place one tube into each of five water baths set at different temperatures.

3. Wait two minutes.

4. Measure the time taken for each piece of pondweed to release 10 bubbles.

What is the independent variable in the investigation?

Table 4 shows the results.

Calculate the rate of photosynthesis at 20 °C.

Give your answer to 3 significant figures.

Give the unit.

Explain the difference in the rate of photosynthesis at 40 °C compared with the rate of photosynthesis at 10 °C.

Give two other factors that affect the rate of photosynthesis.

Do not refer to temperature in your answer.

Describe one way the method could be changed to obtain more accurate results for the rate of photosynthesis.

A gardener noticed that some plants were not growing as well as usual.

Describe two ways the gardener could identify a plant disease.

One of the plants had purple spots on its leaves and the leaves fell off.

What disease is the plant most likely to have?

A different plant had yellow leaves, but no spots.

Explain why plants may develop yellow leaves.

This question is about pathogens.

A scientist investigated antibiotic resistance in bacteria.

Name one antibiotic.

The scientist grew one type of bacterium on agar in a Petri dish.

The scientist placed paper discs each containing a different antibiotic on the agar.

Figure 5 shows the appearance of the Petri dish after 2 days.

A student said:

‘The bacterium is resistant to antibiotic C.’

Explain how the results in Figure 5 show that the student is not correct.

Suggest why doctors are concerned about antibiotic resistance.

Diseases caused by viruses cannot be treated using antibiotics.

Suggest why viruses cannot be grown on agar.

Why is it difficult for scientists to develop drugs to destroy viruses?

Which disease is caused by a virus that damages white blood cells?

Tick (✓) one box.

Viruses cause disease.

What name is given to microorganisms that cause disease?

Tick (✓) one box.

The body has defences to stop viruses entering.

Draw one line from each defence to the part of the body that provides the defence.

Part of the body that

Some viruses can cause tumours to develop.

Complete the sentence.

Choose the answer from the box.

A tumour can form when changes to cells cause uncontrolled

cell.

Malignant tumours are cancers.

Which two sentences describe malignant tumours?

Tick (✓) two boxes.

HPV is a virus that can cause one type of cancer in females.

In the UK since 2008, most 12 to 13-year-old females have been vaccinated against HPV.

Scientists investigated the percentage of 16 to 18-year-old females with HPV.

Table 2 shows the results.

What does Table 2 show about the percentage of females with HPV from 2010 to 2016?

Suggest the reason for the change you described in Question 02.5.

The HPV vaccine contains an inactive form of the virus.

The inactive form of the virus is injected into the body.

Which part of the blood responds to the inactive virus?

Tick (✓) one box.

What is produced by the body in response to the inactive virus?

Tick (✓) one box.

Suggest one reason why some parents refuse to allow their children to have the HPV vaccine.

Do not refer to the pain of the injection in your answer.

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.

Salmonella bacteria cause outbreaks of food poisoning in humans. To prevent food poisoning in humans, farmers vaccinate their animals against Salmonella bacteria.

How do Salmonella bacteria in food cause the symptoms of vomiting and diarrhoea?

During a food poisoning outbreak, scientists identified the farm where the food came from. The farmer had not vaccinated the farm animals against Salmonella bacteria.

The food poisoning outbreak could have been prevented if the farm animals had been vaccinated. Explain how:

• the immune systems of animals respond to a vaccination

• the immune response in farm animals prevents an outbreak of food poisoning in humans.

Most cases of food poisoning do not need to be treated with antibiotics. However, some patients may need to take antibiotics to recover. Scientists investigated the effectiveness of five different antibiotics on the Salmonella bacteria in the outbreak. Antibiotics A, B, C, D and E were used in the investigation. Figure 4 shows the results.

Describe two aseptic techniques the scientists should have used in the investigation.

The scientists incubated the bacteria at 37 °C. Students in school laboratories incubate bacteria at 25 °C. Explain why scientists use 37 °C but students must use 25 °C to incubate bacteria.

What is the purpose of the paper disc with no antibiotic in Figure 4 ?

The scientists concluded that either antibiotic A or antibiotic B should be prescribed to patients with food poisoning. Why should antibiotic A or antibiotic B be prescribed?

The scientists wanted to be more certain about which antibiotic should be prescribed. Describe how the results in Figure 4 could be used to obtain a quantitative comparison of antibiotics A and B.

One year later, there was another outbreak at the farm involving Salmonella bacteria. Antibiotic B did not have an effect. Suggest why antibiotic B no longer had an effect.

Antibiotics treat food poisoning because they kill Salmonella bacteria inside the human body. Some antibiotics work because they damage the bacterial cell wall. The bacteria die because the cells burst. Explain why the cells burst.

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.

HIV (Human Immunodeficiency Virus) is a pathogen.

How is HIV spread from one person to another person?

Tick (✓) one box.

Table 1 shows information about new cases of HIV diagnosed in the UK.

Describe what happened to the number of new cases of HIV from 2010 to 2018.

What could cause a decrease in the number of new HIV cases in the future?

Tick (✓) one box.

Scientists have been working to produce a vaccine for HIV for many years.

How could a vaccine work to prevent a person being infected with HIV?

Write the stages A, B, C, D and E in the correct order.

The first stage has been completed for you.

A Antibodies attach to the inactive virus.

B Antibodies destroy the inactive virus.

C An inactive form of the virus is injected into the body.

D If the active virus enters the body, antibodies are produced quickly.

E White blood cells produce antibodies to the inactive virus.

When scientists produce a vaccine for a disease the vaccine is tested on live animals.

What is the next stage in testing the vaccine?

Tick (✓) one box.

A vaccine for HIV is important because it is difficult to develop safe drugs to destroy viruses.

Why is it difficult to develop safe drugs to destroy viruses?

Tick (✓) one box.

Some drugs originated from plants.

Draw one line from each drug to the plant the drug originated from.

Plant cells and fungal cells are similar in structure.

Figure 10 shows a fungal cell.

Name one structure in Figure 10 which is present in both plant cells and fungal cells but not in animal cells.

Which disease is caused by a fungus?

Tick (✓) one box.

A fungal cell divides once every 90 minutes.

How many times would this fungal cell divide in 24 hours?

Some types of fungal cell are grown to produce high-protein food.

The high-protein food can be used to make meat-free burgers.

Where is protein digested in the human digestive system?

Tick (✓) one box.

Which chemical could be used to test if the burgers contain protein?

Tick (✓) one box.

Table 7 shows some information about burgers made from meat and meat-free burgers.

Evaluate the use of burgers made from meat compared with meat-free burgers in providing humans with a healthy, balanced diet.

Use information from Table 7 and your own knowledge.

Plant cells and fungal cells are similar in structure. Figure 2 shows a fungal cell.

Name one structure in Figure 2 which is present in both plant cells and fungal cells but not in animal cells.

Which disease is caused by a fungus? Tick (✓) one box.

A fungal cell divides once every 90 minutes. How many times would this fungal cell divide in 24 hours?

Some types of fungal cell are grown to produce high-protein food.

The high-protein food can be used to make meat-free burgers.

Where is protein digested in the human digestive system? Tick (✓) one box.

Which chemical could be used to test if the burgers contain protein? Tick (✓) one box.

Table 3 shows some information about burgers made from meat and meat-free burgers.

Evaluate the use of burgers made from meat compared with meat-free burgers in providing humans with a healthy, balanced diet. Use information from Table 3 and your own knowledge.

Turn over for next question

Human immunodeficiency virus (HIV) is a pathogen.

Give one way HIV can spread from one person to another person.

Table 8 shows information about new cases of HIV diagnosed in the UK.

Describe the trends shown in Table 8 between 2010 and 2018.

Suggest one reason for the change in the number of new HIV cases between 2014 and 2018.

Calculate the ratio of new cases of HIV in women to new cases of HIV in men in 2018. Give your answer to 3 significant figures.

In the UK population the total number of women is greater than the total number of men. The data in Table 8 is used to compare the proportions of new cases of HIV in the population for men and women. Suggest how the data could be presented differently so that a more valid comparison can be made.

Scientists have been working to produce a vaccine for HIV for many years.

Explain how a vaccine for HIV could work to prevent a person developing HIV infection.

A person with late stage HIV infection has AIDS. Scientists have produced monoclonal antibodies for HIV. The monoclonal antibodies can prevent a person infected with HIV developing AIDS.

Describe how the monoclonal antibody for HIV can be produced.

Figure 9 shows how HIV enters a human cell.

Suggest how the monoclonal antibody for HIV helps to prevent a person infected with HIV developing AIDS. Use information from Figure 9.

Viruses cause disease.

What name is given to microorganisms that cause disease? Tick (✓) one box.

How do viruses cause the symptoms of disease? Tick (✓) one box.

Figure 4 shows a virus and an animal cell.

Suggest one reason why viruses are not classed as cells.

A vaccine can protect humans from a viral disease.

What does the vaccine contain? Tick (✓) one box.

In some cases, a first vaccination needs to be followed by a second vaccination some time later.

Which graph shows how the concentration of antibodies in a person’s blood changes after the first and second vaccinations? Tick (✓) one box.

Tobacco mosaic virus (TMV) causes disease in plants.

TMV affects the rate of photosynthesis in plants.

Which part of a plant shows discolouration caused by TMV? Tick (✓) one box.

Table 1 shows the rate of photosynthesis in four different tobacco plants.

Complete Figure 5. You should:

• label the y-axis

• add the correct scale to the y-axis

• plot the data from Table 1

• label each bar.

What conclusion can be made from the data in Table 1 ?

Explain why a high level of TMV infection reduces growth in a plant.

The human body can defend itself against microorganisms that cause disease. Viruses are one type of microorganism that cause disease.

Name one type of microorganism that causes disease in humans. Do not refer to viruses in your answer.

Which two defence systems prevent microorganisms infecting the human body? Tick (✓) two boxes.

If microorganisms enter the human body the immune system can destroy the microorganisms. How does the immune system destroy microorganisms? Tick (✓) one box.

Vaccinations prevent people becoming ill with diseases such as measles. Complete the sentences. Choose answers from the box.

If the measles virus enters the body after vaccination the immune system reaction

How is the measles virus spread from one person to another?

Doctors investigated the spread of the virus that causes chickenpox.

The first symptom of chickenpox after exposure to the virus is spots on the body. 23 children were playing together at a party. On the day of the party one of the children developed chickenpox spots. Every two days after the party, the doctors recorded when the other 22 children first showed chickenpox spots. Table 1 shows the results.

What was the range for the days on which children first showed chickenpox spots? Use Table 1.

Incubation time is the usual time from exposure to a pathogen until the first symptoms appear. Suggest the most likely incubation time for chickenpox.

Suggest one reason why some of the children did not develop chickenpox.

One mother gave antibiotics to her child who had chickenpox. Suggest why this child did not recover more quickly than the other children who had chickenpox.

A man has the following symptoms:

• yellow discharge from his penis

• pain when urinating.

The man has a bacterial infection.

What is the most likely cause of the man’s symptoms?

Tick (✓) one box.

The man took a full course of antibiotics.

The man’s symptoms did not improve.

Why did the antibiotics not cure the symptoms?

Tick (✓) one box.

Using a condom can stop the bacteria being passed to another person during sexual intercourse.

Suggest a different way the man could avoid passing the bacteria on to someone else.

A scientist investigated the effect of three different antibiotics on three different types of bacteria, A, B and C.

This is the method used.

1. Grow bacteria A on an agar plate.

2. Put three separate paper discs each containing one of the antibiotics (1, 2 and 3) onto the agar plate.

3. Put the agar plate into an incubator for 48 hours.

4. Repeat steps 1–3 for bacteria B and for bacteria C.

Figure 9 shows the scientist’s results.

Compare the effectiveness of the three antibiotics at killing the different types of bacteria.

Milk contains bacteria.

A small volume of raw milk was placed in a counting chamber in a special type of microscope slide.

Figure 10 shows what the counting chamber looked like when viewed using a microscope.

A scientist counted the number of bacteria in four samples of raw milk.

Table 4 shows the results.

Which milk sample is shown in Figure 10 ?

Tick (✓) one box.

Calculate the mean number of bacteria in the four samples in Table 4.

Calculate the mean number of bacteria per mm³ of milk in the samples.

Complete the following steps.

Calculate the total area of the counting chamber in Figure 10.

The depth of the counting chamber is 0.01 mm

Calculate the volume of the counting chamber in Figure 10.

Use the equation: volume = area depth

Calculate the mean number of bacteria per mm³ of milk in the samples.

Use the equation:

Milk is heated to reduce the number of bacteria it contains before it is sold for humans to drink.

Milk with more than 20 000 bacteria per cm³ cannot be sold for humans to drink.

Table 5 shows the number of bacteria per cm³ in four different samples of milk.

Which of the milk samples could not be sold for humans to drink?

Tick (✓) one box.

Why should milk sold for humans to drink not contain large numbers of bacteria?

Mosquitoes carry a pathogen that causes malaria.

What type of pathogen causes malaria?

Tick (✓) one box.

Mosquito nets can help prevent the spread of malaria.

Table 7 shows the results of a study in one area of Africa.

A newspaper made the following statement:

‘Study shows mosquito nets are scientifically proven to prevent malaria.’

Give one piece of evidence that supports the statement.

Suggest one reason why the statement may not be valid.

Table 8 shows information about the number of deaths from malaria in the same area of Africa.

Predict the number of people per 100 000 who died from malaria in 2017 if the trend stayed the same.

Use of mosquito nets has helped to reduce the number of deaths from malaria each year.

Suggest one other reason for the reduced number of deaths from malaria each year.

Describe how the human body:

• prevents pathogens from entering

• defends itself against pathogens inside the body.

Mosquitoes carry a pathogen that causes malaria.

What type of pathogen causes malaria?

Tick (✓) one box.

Mosquito nets can help prevent the spread of malaria.

Table 1 shows the results of a study in one area of Africa.

A newspaper made the following statement:

‘Study shows mosquito nets are scientifically proven to prevent malaria.’

Give one piece of evidence that supports the statement.

Suggest one reason why the statement may not be valid.

Table 2 shows information about the number of deaths from malaria in the same area of Africa.

Predict the number of people per 100 000 who died from malaria in 2017 if the trend stayed the same.

Use of mosquito nets has helped to reduce the number of deaths from malaria each year.

Suggest one other reason for the reduced number of deaths from malaria each year.

Describe how the human body:

• prevents pathogens from entering

• defends itself against pathogens inside the body.

Aphids are small insects that carry pathogens.

Figure 7 shows an aphid feeding from a plant stem.

An aphid feeds by inserting its sharp mouthpiece into the stem of a plant.

After feeding, the mouthpiece of an aphid contains a high concentration of dissolved sugars.

Which part of the plant was the aphid feeding from?

Tick one box.

What is the process that transports dissolved sugars around a plant?

Plants infected with aphids have stunted growth.

Explain one way the removal of dissolved sugars from the stem of the plant causes stunted growth.

Most aphids do not have wings when they hatch. After several generations, some aphids hatch which have wings and can fly.

Explain the advantage to the aphid of being able to fly.

The leaves of some plants release oils onto their surface.

Suggest how the production of oil on the surface of a leaf may protect the plant from aphids.

Figure 8 shows part of a rose plant.

Give one adaptation shown in Figure 8 that helps the rose plant defend itself.

Figure 9 shows a plan of a garden containing rose plants.

Plant A has the fungal disease rose black spot.

Which plant in Figure 9 is the fungus likely to spread to first?

Give a reason for your answer.

Suggest one way the gardener could reduce the spread of rose black spot to the other plants in the garden.

Eating food containing Salmonella bacteria can cause illness.

Two symptoms of infection by Salmonella are vomiting and diarrhoea.

What causes these symptoms?

Give two ways a person with a mild infection of Salmonella can help prevent the spread of the bacteria to other people.

In very serious infections of Salmonella, a doctor can prescribe drugs to kill the bacteria.

What type of drug can the doctor prescribe to kill the bacteria?

A person with AIDS may take longer than a healthy person to recover from a Salmonella infection.

Explain why.

Salmonella bacteria can be transmitted from chickens to humans. Chickens can be vaccinated to prevent the transmission of Salmonella bacteria to humans.

Suggest one other way farmers could prevent the transmission of Salmonella from chickens to humans.

A restaurant owner employed a scientist to test the effectiveness of two kitchen cleaning liquids.

The scientist took samples from two work surfaces:

before the surfaces had been cleaned with the cleaning liquids

after the surfaces had been cleaned with the cleaning liquids.

The samples were then analysed for the number of bacteria they contained.

The results are shown in Figure 10.

Which cleaning liquid is the more effective?

Give a reason for your answer.

The scientist investigated the effect of cleaning liquid A and cleaning liquid B on Salmonella bacteria grown in a laboratory.

Figure 11 shows the way the investigation was set up.

The Petri dish was placed in an incubator at 25 °C for 48 hours.

After 48 hours, the scientist calculated the area around each paper disc where no bacteria were growing.

The results are shown in Table 4.

What measurement would the scientist need to take to calculate the area where no bacteria were growing?

Give one change to the investigation that would allow the scientist to check if the results are repeatable.

The scientist showed the results to the restaurant owner.

Both cleaning liquids cost the same per dm³.

Suggest one other factor the restaurant owner should consider when choosing which cleaning liquid to use.

Eating food containing Salmonella bacteria can cause illness.

Two symptoms of infection by Salmonella are vomiting and diarrhoea.

What causes these symptoms?

Give two ways a person with a mild infection of Salmonella can help prevent the spread of the bacteria to other people.

In very serious infections of Salmonella, a doctor can prescribe drugs to kill the bacteria.

What type of drug can the doctor prescribe to kill the bacteria?

A person with AIDS may take longer than a healthy person to recover from a Salmonella infection.

Explain why.

Salmonella bacteria can be transmitted from chickens to humans. Chickens can be vaccinated to prevent the transmission of Salmonella bacteria to humans.

Suggest one other way farmers could prevent the transmission of Salmonella from chickens to humans.

A restaurant owner employed a scientist to test the effectiveness of two kitchen cleaning liquids.

The scientist took samples from two work surfaces:

before the surfaces had been cleaned with the cleaning liquids

• after the surfaces had been cleaned with the cleaning liquids.

The samples were then analysed for the number of bacteria they contained.

The results are shown in Figure 1.

Which cleaning liquid is the more effective?

Give a reason for your answer.

The scientist investigated the effect of cleaning liquid A and cleaning liquid B on Salmonella bacteria grown in a laboratory.

Figure 2 shows the way the investigation was set up.

The Petri dish was placed in an incubator at 25 °C for 48 hours.

After 48 hours, the scientist calculated the area around each paper disc where no bacteria were growing.

The results are shown in Table 1.

What measurement would the scientist need to take to calculate the area where no bacteria were growing?

Give one change to the investigation that would allow the scientist to check if the results are repeatable.

The scientist showed the results to the restaurant owner.

Both cleaning liquids cost the same per dm³.

Suggest one other factor the restaurant owner should consider when choosing which cleaning liquid to use.