Health and disease

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.

Which disease may develop due to an interaction with HPV?

A AIDS

B Cervical cancer

C Tuberculosis

D Type 2 diabetes

There are interactions between some types of disease.

Which is an example of two diseases that interact?

A Cervical cancer and HPV

B Cervical cancer and tuberculosis

C HIV and HPV

D HPV and tuberculosis

HIV and TB (tuberculosis) are infectious diseases.

HIV is spread between humans during sexual intercourse when body fluids come into contact.

TB is a disease caused by bacteria. It affects the lungs.

Explain how TB is spread between humans.

Describe how the lungs defend the body against infection from TB bacteria.

The lungs can also be affected by cancer.

Complete these sentences to describe what cancer is.

Use the words in the list.

differentiated meiosis mitosis multiple undifferentiated

Cancer is the result of uncontrolled growth when cells divide by........

This may lead to millions of........ cells that are unable to become specialised.

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.

This question is about diseases.

Complete the table to compare some different diseases.

Tick (✓) five boxes.

Tuberculosis has been done for you.

TB is a disease of the lungs. TB is transmitted by breathing in when an infected person near you coughs or sneezes.

One way to prevent the spread of TB is vaccination.

Describe two other ways you could prevent the spread of TB.

There are many diseases and disorders of the circulatory system.

Some blood cell disorders can affect the function of white blood cells or red blood cells.

Suggest two effects on the body if either white blood cells or red blood cells are prevented from working efficiently.

Cardiovascular diseases affect the heart.

Which lifestyle factor can increase a person’s chance of developing cardiovascular disease?

Tick (✓) one box.

*(c) The cornea is the front part of the eye that allows in light. The layers of cells in the cornea are similar to the cells in skin layers, the difference is that they have become transparent to allow the light through.

Scientists are now using stem cell technology for treating damage to the cornea to restore vision.

Describe how stem cells could be used in the treatment of damage to the cornea and any possible risks involved in this type of treatment.

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.

The graph shows the annual number of cancer cases worldwide and the number of cases triggered by HPV infections.

From evidence in the graph, which cancer is linked most strongly to HPV infections?

A Cervical cancer

B Vaginal cancer

C Mouth cancer

D Throat cancer

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?

If a person has one disease, it is sometimes more likely that they will develop another disease.

Which pair of diseases affects each other this way?

A HIV infection and cervical cancer

B HPV infection and cervical cancer

C HPV infection and tuberculosis

D Tuberculosis and cervical cancer