Discovery & development of drugs

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.

Cancer occurs when there is uncontrolled cell division.

Which two factors can cause cancer?

Tick () two boxes.

What type of cell division occurs in cancerous cells?

Tick () one box.

Complete the sentences.

Choose answers from the box.

Figure 4 shows the cell cycle.

What percentage of the time taken for the cell cycle does the cell growth stage take?

Use Figure 4.

Tick () one box.

What happens during stage X of the cell cycle in Figure 4 ?

Tick () one box.

Figure 5 shows an animal cell during cell division.

Name structure Z in Figure 5.

The image of the cell in Figure 5:

• is magnified 800 times

• has a width of 50 mm.

Calculate the real width of the cell in Figure 5.

Give your answer in micrometres (µm).

Use the equation:

1 mm = 1000 µm

Some drugs can treat cancer.

Complete the sentences.

Choose answers from the box.

In drug trials some patients are given a tablet which does not contain the drug.

What name is given to the tablet that does not contain the drug?

Cancer is caused by changes in cells that result in uncontrolled cell division.

Before a cell begins to divide, its DNA replicates to form two copies of each chromosome.

Describe one other change that occurs in a cell before the cell begins to divide.

Figure 8 shows a cell during one of the stages of cell division.

Name structure Z in Figure 8.

Structure Y in Figure 8 is a cylinder.

For structure Y:

• real volume = 24 500 000 nm³

• real radius = 125 nm.

The length of a cylinder is calculated using the equation:

The length of the image of structure Y in Figure 8 is 4 mm.

Calculate the magnification of structure Y in Figure 8.

Use π = 3.14

Magnification = ×

Figure 9 shows some of the stages of cell division.

Some cancer drugs prevent cell division.

Drug X prevents the fibres from attaching to the replicated chromosomes in stage 1.

Explain why a cell cannot complete division when affected by drug X.

Give the reason why a drug that stops cell division helps to treat cancer.

New cancer drugs are tested in clinical trials.

Preclinical testing happens before clinical trials.

What is involved in preclinical testing of drugs?

Tick (✓) one box.

A root is a plant organ.

Plant roots contain many different types of tissue.

What is a tissue?

Tissue in the tip of a plant root contains stem cells.

Stem cells can differentiate into any type of cell.

Name the type of tissue in plants that contains stem cells.

In the past many drugs were extracted from plants.

Aspirin is a painkiller.

Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant.

Chemical A can be used as a painkiller.

Table 5 shows information about where chemical A is found.

The scientists usually extract chemical A from the berries of the deadly nightshade plant.

Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves).

The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 5.

Calculate the mass of chemical A in 200 g of the leaves with chlorosis.

Give your answer in mg.

Suggest one reason why the leaves of the deadly nightshade plant have chlorosis.

Chemical A has not been tested in large-scale clinical trials in the UK.

It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public.

Give two reasons why.

There are many online reports making claims about the effects of chemical A.

Some of these reports are biased.

Suggest one reason why a report making claims about the effects of chemical A may be biased.

How can scientists be sure that claims about new drugs are valid?

Tick (✓) one box.

A root is a plant organ. Plant roots contain many different types of tissue.

What is a tissue?

Tissue in the tip of a plant root contains stem cells. Stem cells can differentiate into any type of cell. Name the type of tissue in plants that contains stem cells.

In the past many drugs were extracted from plants.

Aspirin is a painkiller. Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant. Chemical A can be used as a painkiller. Table 1 shows information about where chemical A is found.

The scientists usually extract chemical A from the berries of the deadly nightshade plant. Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves).

The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 1.

Calculate the mass of chemical A in 200 g of the leaves with chlorosis. Give your answer in mg.

Suggest one reason why the leaves of the deadly nightshade plant have chlorosis.

Chemical A has not been tested in large-scale clinical trials in the UK.

It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public. Give two reasons why.

There are many online reports making claims about the effects of chemical A. Some of these reports are biased.

Suggest one reason why a report making claims about the effects of chemical A may be biased.

How can scientists be sure that claims about new drugs are valid? Tick (✓) one box.

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.

Figure 7 shows part of a deadly nightshade plant.

How will the poisonous berries help the deadly nightshade plant to survive?

Which type of defence mechanism are the berries? Tick (✓) one box.

Figure 8 shows part of a gorse plant.

Suggest how the gorse plant is adapted to defend itself.

The green leaves of the gorse plant make glucose for the plant to use. What are two uses of glucose in the gorse plant? Tick (✓) two boxes.

A student wanted to show that the leaves of a gorse plant contain glucose. The student crushed the leaves to extract the liquid from the cells. Describe the method the student could use to test the liquid from the cells for glucose. Include the result if glucose is present.

The roots of the gorse plant have bacteria that turn nitrogen gas into nitrate ions. Explain why nitrate ions are needed by the gorse plant.

The roots of gorse plants can be infected by honey fungus. The honey fungus produces tiny spores underground. Suggest how the honey fungus spores travel from the roots of an infected gorse plant to the roots of a healthy gorse plant.

A drug can be extracted from gorse seeds.

Doctors want to trial the drug from gorse seeds to see if it can treat diarrhoea.

Which two factors must the doctors test the drug for in the trial? Tick (✓) two boxes.

In the trial some patients will take tablets made from gorse seeds and some patients will take tablets made from sugar. What are the tablets made from sugar called? Tick (✓) one box.

Many plants have evolved defence mechanisms. Figure 8 shows part of a gorse plant and part of a deadly nightshade plant.

The gorse plant has evolved to have sharp thorns. What type of defence response are thorns?

How do thorns defend the gorse plant?

The deadly nightshade plant has poisonous berries. What type of defence response are poisonous berries?

A scientist noticed that in one area the gorse plants had yellow leaves and had stunted growth. One reason for yellow leaves and stunted growth is a deficiency of nitrate ions in the soil. Explain two other possible reasons for the yellow leaves and stunted growth. Do not refer to nitrate ions in your answer.

The gorse plant has nodules on its roots.

The nodules are part of the living root tissue. Bacteria which convert nitrogen gas into soluble nitrate ions live in the nodule tissue. Figure 9 shows the nodules on the roots.

Suggest how the nodules benefit the bacteria.

Explain how the nodules benefit the gorse plant.

For many years drugs have been extracted from plants. Which plant material was chewed as a painkiller? Tick (✓) one box.

There are no questions on this page

Monoclonal antibodies (mAbs) are usually made using mouse lymphocytes. Candida albicans infection produces serious symptoms in patients with a poor immune system. Recently scientists have produced mAbs to Candida albicans using human lymphocytes produced naturally after an infection.

Candida albicans lives in the throat of infected patients. A sample is taken from the throat of a patient with a suspected Candida albicans infection. The sample is transferred onto a microscope slide. Describe how the mAbs and a fluorescent dye could be used to see any Candida albicans pathogens on the slide.

In a laboratory the human lymphocyte mAbs were injected into animals infected

with Candida albicans. The mAbs caused increased phagocytosis of the Candida albicans pathogens. Doctors intend to start a trial to give the mAbs to patients severely ill with Candida albicans.

Explain how increased phagocytosis of the Candida albicans pathogen will help the patient.

It has been shown that this mAbs treatment is effective in the laboratory using both:

• infected tissue culture cells

• infected live animals.

The mAbs treatment for Candida albicans is now ready for clinical trials on people. Describe how the clinical trials should be carried out.

Scientists have also used human lymphocytes to make mAbs to other pathogens and to some types of cancer cells. Suggest one reason why these new mAbs have been more successful in treating diseases in humans than mAbs made using mice.

A small animal called an axolotl lives in water. The axolotl has a double circulatory system.

Define the term double circulatory system.

Figure 7 shows the double circulatory system of the axolotl.

Figure 7

The following figure cannot be reproduced here due to third-party copyright restrictions.

The heart of the axolotl has only one ventricle.

Label the ventricle on Figure 7.

Explain why having only one ventricle makes the circulatory system less efficient than having two ventricles.

Figure 8 shows an axolotl.

Explain why an axolotl may die in water with a low concentration of oxygen.

If a gill of an axolotl is removed, a new gill will grow in its place.

Scientists hope to use information on how axolotls grow new gills to help with regenerating human tissue.

Name the type of cell that divides when a new gill grows.

Name one condition that could be treated using regenerated human tissue.

Suggest one reason why an axolotl is a suitable animal for research in the laboratory.

An axolotl may not be a suitable animal to study when researching regeneration in human tissue.

Suggest one reason why.

Pancreatic cancer develops when a malignant tumour grows inside the pancreas.

The pancreas produces digestive enzymes. What is an enzyme?

Carbohydrase is an enzyme produced by the pancreas.

Name two other organs in the digestive system that produce carbohydrase.

One symptom of pancreatic cancer is weight loss. Explain how pancreatic cancer may cause a person to lose weight. Do not refer to hormones in your answer.

Enzyme A and enzyme B are involved in controlling cell division in pancreatic cancer cells. Most cancer cells produce both enzyme A and enzyme B. Some people have a gene mutation that stops cancer cells producing enzyme B.

Figure 9 shows how cell division is controlled in pancreatic cancer cells.

Scientists have developed a drug that inhibits enzyme A. The drug is given to pancreatic cancer patients who have the gene mutation that stops cancer cells producing enzyme B. The drug only targets cancer cells.

Explain why the drug can be used to treat pancreatic cancer in patients with the gene mutation.

Use information from Figure 9.

Explain why the drug could not be used to treat pancreatic cancer in a patient that produces both enzyme A and enzyme B.

The drug was trialled before it was licensed for use. To improve validity of the results in the trial:

• some patients were given a placebo

• a double-blind trial was used.

Give reasons why a placebo and a double-blind trial were used.

A double-blind trial

One stage in a drug trial is to test the drug on healthy volunteers.

What is the next stage in the drug trial?

Tick (✓) one box.

A monoclonal antibody has been produced to treat pancreatic cancer.

Explain how the monoclonal antibody works to treat pancreatic cancer.