Health & disease

What is the correct treatment for a disease caused by viruses?

A Antibiotics

B Antivirals

C Progesterone

D Insulin

A student wants to find how effective three antibiotics are for treating a range of bacterial infections.

This is their method:

• Spread bacteria across an agar plate.

• Soak discs with different antibiotics (A, B and C) and place them on the surface of the agar plate.

• Leave the plate to incubate for 5 days.

The student’s results are shown in the diagram.

Antibiotic discs

Which antibiotics are the most and least effective at inhibiting bacteria growth?

Most effective antibiotic A B C

Least effective antibiotic A B C

Explain your answers. Use the diagram.

Suggest two improvements to the method to increase validity of the investigation.

Bacteria are one cause of communicable disease.

Outline the role of the immune system of the human body in defence against disease.

Tuberculosis (TB) is caused by bacteria. The bacteria usually attack the lungs.

It is estimated that 8.7 million people develop TB worldwide each year.

1.1 million of these people are estimated to have HIV.

Calculate the percentage of people who develop TB worldwide each year who are estimated to have HIV.

Infection with HIV makes you more likely to develop TB.

State one reason why having HIV makes you more likely to develop TB.

Antibiotics are developed to kill bacteria.

Bacteria have appeared that antibiotics can not kill.

Explain how bacteria could have evolved to become antibiotic resistant.

Use ideas about natural selection.

New medicines are developed all the time.

Insulin is a protein used to treat diabetes. The human stomach contains an enzyme that is specific to proteins like insulin.

Suggest why it is difficult to develop an insulin medicine that is swallowed.

Which type of medicine has been developed to treat HIV?

antibiotic antigen antiseptic antiviral

Some diseases are treated by changes to lifestyle.

Complete these sentences about cardiovascular disease.

The risk of cardiovascular disease is reduced by a........ low in saturated fat.

This reduces the risk of blocked arteries therefore allowing more oxygen to be transported to the

........ muscle in the ventricle wall.

Which is an example of an antiseptic?

A A chemical injected into the blood to prevent infection.

B A drug taken as a tablet to reduce an infection.

C Cream put on the skin to kill harmful microorganisms.

D Part of a pathogen that triggers an immune response.

Tuberculosis is a disease of the lungs. The number of cases of tuberculosis in the UK between 1914 and 1987 decreased from 99 497 to 5086.

Which could be a reason for this decrease?

A Development of a vaccine for tuberculosis

B Development of industrial processes that produce pollution

C Increase in population between 1914 and 1987

D Increase in the number of people who smoke

A student investigates the effect of antibiotics on the growth of bacteria.

This is the method they follow:

• Place discs of paper containing different antibiotics on an agar plate containing bacteria.

• Leave the agar plate in a warm place.

• Observe the growth of the bacteria after three days.

The diagram shows their results. Clear zones around the antibiotic discs show where the bacteria growth is inhibited.

What are the independent variable and the dependent variable for this investigation?

Independent variable........

Dependent variable........

Explain why the student uses a disc with no antibiotics on it.

Which antibiotic, A – E, is the most effective?

Explain your answer.

After the student has recorded their results the agar plates are destroyed.

Why should agar plates containing bacteria be destroyed?

Suggest how the student could develop their investigation to show the effect of antibiotic on the growth of different bacteria.

What medicine can be used to treat tuberculosis?

A Antibiotics

B Antiseptics

C Antitoxins

D Antivirals

The deaths in one country from different diseases were measured over a 40-year period.

Lifestyle and living conditions in this country changed during the 40 years of the study.

The graph shows the number of deaths per 100 000 of the population for each disease.

The diseases can be grouped into communicable and non-communicable diseases. The graph shows the trends of these two different types of disease over the 40-year period.

Complete the sentences explaining these trends shown in the graph.

Communicable diseases have........

Non-communicable diseases have........

Suggest how lifestyle and living conditions in this country might have changed to cause the trends shown in the graph.

To calculate the death rate in a given year, the following formula is used:

In 1972, the population was 55 million. The death rate from coronary heart disease was 28 deaths per 100 000 people.

Calculate the number of deaths from coronary heart disease in 1972.

The immune system provides a defence against bacterial diseases like TB (tuberculosis).

Part of this defence involves the production of antibodies.

Describe how antibodies help defend the body. Use ideas about antigens in your answer.

What does a vaccination contain and why does it protect the body from infection?

Vaccinations contain........

Vaccinations protect the body because........

HPV (human papilloma virus) is a pathogen that causes cervical warts.

The graph shows data for HPV vaccination rates from a country where women are screened for cervical cancer.

Use the graph to describe the relationship between the HPV vaccination and risk of cervical cancer.

Explain how the vaccine for HPV prevents the pathogen causing cervical warts.

Describe the relationship between health and disease.

HPV (human papilloma virus) causes cervical warts.

Fig. 13.1 is a diagram representing the size of HPV as it would be seen using an electron

The HPV shown in Fig. 13.1 has a diameter of 50 mm. The actual HPV has a diameter of 55 nanometres.

Calculate the magnification of the HPV shown in Fig. 13.1.

Give your answer to 2 significant figures.

Magnification = ×........

Women can be given a vaccine to protect against HPV.

Explain why the vaccine produces an immune response to HPV but does not cause cervical warts.

Describe two ways scientists test new vaccines to ensure they are safe for humans.

A patient has a urinary tract infection caused by bacteria. The doctor needs to know the best antibiotic to use to treat the infection.

They send a sample of the patient’s urine for testing. The bacteria in the urine are grown on agar jelly plates. On the plates are four different antibiotic discs.

Aseptic techniques are used to prepare the agar jelly plates.

Fig. 12.1 shows the neck of a glass bottle containing the agar jelly being heated in a flame for 2 seconds. This is done before the agar jelly is poured into the Petri dish.

Suggest why the scientist uses a glass bottle and not a plastic bottle.

The neck of the glass bottle is heated before transferring the agar jelly to the Petri dish.

Explain why.

Fig. 12.2 shows the results of the four different antibiotics A, B, C and D.

The line XY is the diameter of clear agar jelly for Antibiotic A.

Use the line XY to calculate the cross-sectional area of clear agar jelly for Antibiotic A

The area of a circle = r²

= 3.14

Give your answer to 3 significant figures.

Some bacteria are resistant to antibiotics.

Explain why antibiotic resistant bacteria show evidence of evolution.

A surface graze on the skin might get infected.

Which of these is usually used to prevent infection of grazed skin?

A Antibiotic

B Antiseptic

C Antiviral

D Vaccination

HIV is a virus that causes AIDS.

Some countries have set up centres where a person is counselled and tested for HIV.

The aim is to reduce new infections by 50%.

Write down two types of testing that can be done to identify someone with HIV.

Humans who contract HIV do not die from the virus. Instead they die from AIDS-related diseases such as tuberculosis (TB).

HIV infects human cells by inserting genes into the cells. The human cells then copy the genes.

TB is caused by bacteria that infect the lungs.

Explain why a person with HIV is more likely to die from TB than a person without HIV.

Use ideas about the immune system in your answer.

HIV can be transmitted during unprotected sexual intercourse.

Name one method of contraception and explain why it prevents the transmission of HIV.

Name of method of contraception........

Why it prevents the transmission of HIV........

Scientists are trying to develop a vaccine against HIV.

Explain how a vaccine could protect people against HIV.

Which type of medication can be used to treat people who already have HIV?

Antiviral drugs can work in different ways.

Which statement shows how an antiviral drug can work?

A It acts as a vaccine against the virus.

B It causes phagocytosis of the virus.

C It contains antibiotics to destroy the virus.

D It stops the virus releasing its genetic material.