Spread of disease

Figure 15 shows the number of new cases of chlamydia diagnosed in England from 2013 to 2022.

Which type of organism causes chlamydia?

Calculate the increase in the number of new cases of chlamydia diagnosed from 2020 to 2022.

Tuberculosis is a disease that is spread through airborne droplets.

Give two ways of reducing or preventing the spread of tuberculosis.

Obesity is a risk factor for some non‑communicable diseases.

State why liver disease is a non-communicable disease.

The waist‑to‑hip ratio can be used to show if excess weight is a health risk.

An adult has a waist measurement of 80 cm and a hip measurement of 90 cm.

Calculate the waist‑to‑hip ratio for this adult, using the equation:

Give your answer to two decimal places.

waist‑to‑hip ratio_........

Figure 16 shows the health risk of some waist‑to‑hip ratios.

Explain the health risk for a female with a waist‑to‑hip ratio of 0.75.

Cancer occurs when cell division by mitosis is uncontrolled.

Describe the properties of cells produced by mitosis.

Tuberculosis is a disease that is spread through airborne droplets.

Give two ways of reducing or preventing the spread of tuberculosis.

Obesity is a risk factor for some non‑communicable diseases.

State why liver disease is a non-communicable disease.

The waist‑to‑hip ratio can be used to show if excess weight is a health risk.

An adult has a waist measurement of 80 cm and a hip measurement of 90 cm.

Calculate the waist‑to‑hip ratio for this adult, using the equation:

Give your answer to two decimal places.

waist‑to‑hip ratio_........

Figure 2 shows the health risk of some waist‑to‑hip ratios.

Explain the health risk for a female with a waist‑to‑hip ratio of 0.75.

Cancer occurs when cell division by mitosis is uncontrolled.

Describe the properties of cells produced by mitosis.

The pathogen Vibrio cholerae causes the disease cholera.

Figure 7 shows Vibrio cholerae bacteria.

Complete the table to show the function of structure P and structure Q.

On the original image, the length of one bacterial cell is 12 mm.

The actual length of this bacterial cell is 2.0 µ m.

Calculate the magnification.

State one symptom of the disease caused by Vibrio cholerae.

State how the disease caused by Vibrio cholerae is transmitted.

Describe the specific immune response when a pathogen infects the body.

Malaria is a disease that causes damage to the blood and liver.

Which type of pathogen causes malaria?

State how the pathogen that causes malaria is spread.

Measles is a disease caused by a virus.

Figure 4 shows the number of measles cases reported in England and Wales from 1985 to 2015.

Explain one conclusion that can be made about the change in the number of measles cases reported from 1985 to 2015.

Describe two ways the immune system will respond to an infection by a pathogen.

Beriberi is a disease caused by a lack of vitamin B1 in the diet.

Give one reason why beriberi is classed as a non‑communicable disease.

Figure 9 shows an aphid.

An aphid inserts its mouthpart into plant tissue to feed on plant sap.

(Source: http://www.biology-resources.com/drawing-aphid-wingless.html)

Figure 9

Aphids can transfer plant viruses from one plant to another.

Which term describes the role of the aphid in the transmission of plant viruses?

Describe the physical barriers of a leaf that the virus gets through when an aphid feeds.

The genetic material from the virus is transcribed by the plant cell.

Describe how mRNA is produced during transcription.

Name the stage of protein synthesis after transcription.

Biological control can be used on aphid populations feeding on crops.

Explain the advantages of using biological control on aphid populations.

Stomach ulcers can be caused by bacteria.

Name the bacteria that cause stomach ulcers.

People with a stomach ulcer are treated with antibiotics and an alkaline medicine to reduce symptoms.

Give a reason why the alkaline medicine is used.

Antibiotics are used to treat stomach ulcers.

Bacteria have become resistant to some antibiotics.

A scientist has an agar plate spread with the bacteria that cause stomach ulcers and discs containing different antibiotics.

Describe how the scientist could use these to determine which antibiotic can kill the bacteria.

*(c) A bacteriophage is a type of virus that can infect bacterial cells.

Figure 12 shows a bacteriophage infecting a bacterial cell.

Scientists are investigating if a bacteriophage could be used as an alternative to antibiotics.

Describe the lytic lifecycle of a virus and suggest why a bacteriophage could be used as an alternative to antibiotics.

Plant growth can be affected by the environment, by pathogens, or both.

A farmer found lesions on crop plants growing in one of their fields.

Figure 11 shows lesions on leaves.

*(i) Discuss how the cause of the lesions and their spread through the crops could be investigated.

You should refer to distribution analysis in your answer.

The farmer decides to dig up the affected crop plants.

Give one precaution the farmer should take when digging up the affected crop plants.

The genetic material of some plant viruses is single-stranded RNA.

The RNA is copied by the infected host cell and acts as a mRNA molecule.

Describe how protein synthesis makes viral proteins from this mRNA.

Some bacteria cause disease.

Which word describes an organism that causes disease?

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

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A scientist investigated the effect of temperature on the growth of bacteria.

The bacteria were grown at 10 °C and 20 °C.

The number of bacteria grown at each temperature were counted every two hours.

Figure 1 shows the result.

Figure 2 shows a graph of the results at 20 °C.

Plot the points on the graph for the number of bacteria at 10 °C.

The first two points have been plotted for you.

Draw a line of best fit on the graph for 10 °C.

Describe how the growth of bacteria at 10 °C was different from the growth of bacteria at 20 °C.

Figure 2 shows the number of people diagnosed with sexually transmitted infections (STIs) in the UK during 2017.

State the sexually transmitted infection that has the median number of people diagnosed.

The population of the UK in 2017 was 66 million people.

Calculate the total number of people diagnosed with chlamydia in the UK in 2017.

State why chlamydia can be described as a communicable disease.

Give one way the transmission of chlamydia can be prevented.

Explain why chlamydia can be treated with antibiotics.

HIV is another sexually transmitted infection.

Explain how HIV can lead to the onset of AIDS.

9 (a) Name the organisation which defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.

(b) Tuberculosis (TB) is a communicable disease.

(i) State two ways that communicable diseases are different from non-communicable diseases.

(ii) Explain one way that the spread of tuberculosis (TB) can be reduced or prevented.

* (c) Describe how the physical barriers and chemical defences of the human body provide protection from diseases.

3 (a) Name the organisation which defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.

(b) Tuberculosis (TB) is a communicable disease.

(i) State two ways that communicable diseases are different from non-communicable diseases.

(ii) Explain one way that the spread of tuberculosis (TB) can be reduced or prevented.

Complete the table to show the student’s data.

(c) Explain why people with AIDS are more susceptible to TB.

Measles is a communicable disease caused by a virus.

What can a virus also be classified as?

Give one reason why measles is described as a communicable disease.

The human immunodeficiency virus (HIV) can cause AIDS.

Which type of cell is destroyed by the HIV virus?

Describe how the specific immune system defends the body against disease.

Figure 13 shows the number of people per million of the population in five European countries who were diagnosed with measles in one year.

The population of Belgium in that year was 11.18 million.

Calculate the number of people in Belgium diagnosed with measles.

Give your answer to three significant figures.

Countries do not report the total number of people diagnosed with measles. Countries report the number of people diagnosed with measles per million of the population.

Give one reason why this is better.

Give one reason why the number of people per million diagnosed with measles is different in these countries.

Between 2013 and 2016 there was an outbreak of a disease called Ebola.

Ebola is estimated to have caused the deaths of more than 11 000 people.

Why is the number of deaths from Ebola only an estimate?

State how Ebola is spread from person to person.

The lytic pathway is part of the lifecycle of the Ebola virus.

After infection of the host cell, components of the virus are produced.

Describe the next stages of the lytic pathway.

The genetic material of a virus can also be inserted into the genome of the host.

Name this type of pathway.

State what is meant by the term genome.

Pathogens cause disease.

Draw one straight line from each type of pathogen to the disease that is caused by that pathogen.

Antibiotics can be used to treat diseases.

Antibiotics kill

Figure 1 shows the number of white blood cells in blood samples from three patients.

Explain why the data suggests that Patient Z has a bacterial infection.

HIV is diagnosed by blood tests.

State two safety precautions that need to be taken when handling blood samples.

Streptococcus bacteria can cause a sore throat or skin infection.

An illness called scarlet fever can also develop during an infection with this bacterium.

Give two precautions a doctor should take when treating a patient who is infected with Streptococcus.

From September 2013 to March 2014 there were 2 830 cases of scarlet fever in the UK.

From September 2014 to March 2015 there were 5 943 cases of scarlet fever.

Calculate the percentage increase of the number of cases of scarlet fever between the periods September 2014 to March 2015 and September 2013 to March 2014.

Figure 10 shows some Streptococcus bacteria.

Some bacteria are motile, meaning they can move themselves.

Why is a Streptococcus bacterium not motile?

Patients with scarlet fever can be treated with antibiotics.

New antibiotics need to be tested before they can be used in patients.

Which is the correct sequence for the development of a new medicine?

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Most cases of scarlet fever occur in children.

Adults have usually developed immunity to a toxin that the Streptococcus bacteria produce during infection.

Explain how an adult develops immunity to the toxin.