OCR GCSE Combined Science A (Gateway) Biology Paper 2 Foundation June 2019 question paper J250/02

Which cell is adapted to defend the body from infection?

What do antibodies bind to when they defend the body?

A Antigens

B Platelets

C Red blood cells

D White blood cells

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

A pooter is used to sample populations.

Which type of animal would be sampled using a pooter?

A Beetle

B Bird

C Fish

D Mouse

Which combination of sex chromosomes is correct for humans?

A female XX male XX

B female XY male XX

C female XX male XY

D female XX male YY

Huntington’s disease is a single gene disorder caused by a dominant allele (H).

The Punnett square shows the genetic cross between two heterozygous parents.

What is the probability of these parents having a child with Huntington’s disease?

A 0 in 4

B 1 in 4

C 2 in 4

D 3 in 4

Which word describes the number of chromosomes in a human sperm cell?

A Diploid

B Dominant

C Haploid

D Recessive

In 2008 there were 16 600 people with liver disease. Of these, 600 survived liver disease due to a liver transplant.

Calculate the percentage of people with liver disease who survived because of a liver transplant in 2008.

A 3.6%

B 3.7%

C 26.7%

D 27.7%

Look at the bacterial cell that causes disease.

The human eye can see objects 0.1 mm in size.

What minimum magnification will be needed before the eye can see this bacterial cell?

A 1.25×

B 12.5×

C 125×

D 1250×

Two students want to see if the length of a pea pod affects the number of pea seeds inside the

They measure the length of pea pods in millimetres using a ruler. They open the pods and count the pea seeds inside.

What is the independent variable in their investigation?

Tick (✓) one box.

Write down two variables they need to control to make the data valid.

The students choose five pea pods with a length of between 45 – 55 mm and count the number of seeds inside each pod.

Look at their results.

Calculate the mean number of seeds.

Write your answer in the table.

Use your answer to part (b)(i) to calculate the length of pod per seed.

The students repeat the experiment for pea pods between 65 – 75 mm.

The mean number of seeds was 6.7 and length of pod per seed was 11.2 mm.

Write down two conclusions from this experiment.

How could the students make sure the samples they collect are representative?

The phenotype of peas is controlled by many factors.

Write down two environmental factors that could affect pea pod length.

Early genetic studies identified the colour of pea pods as green or yellow. Results suggested that the colour is an example of single gene inheritance.

Why is it not easy to work out the genotype of skin colour in humans?

HIV is a virus that causes AIDS.

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

In which part of a human cell are HIV genes copied?

chloroplast cytoplasm mitochondria nucleus

In the laboratory, scientists have used gene technology to completely remove HIV genes from infected cells.

Explain how removing HIV genes could affect the spread of HIV.

Suggest why some people are concerned about the use of gene technology in HIV treatment.

The Human Genome Project mapped the human genome.

Write down what is meant by the term genome.

Knowledge of the human genome could identify the genes affected by HIV.

Write down two ways knowledge of the human genome could help with the treatment of HIV.

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

The aim is to reduce new infections by 50%.

Describe how HIV is transmitted and how these centres can contribute to reducing the spread of HIV.

HIV invades white blood cells stopping them working.

Describe the role of white blood cells in the defence against disease.

The diagrams show two Blue Moon butterflies.

The two butterflies are the same species. However, there are differences between the colour and wing shape of the two butterflies.

What controls the colour and wing shape within the species?

Evolution can take thousands of years, but occasionally change happens very quickly.

Read the information.

Male embryos of the Blue Moon butterfly were attacked by a parasite.

Only 1% of the male butterfly population survived.

Within ten generations (1 year) males had returned to 40% of the butterfly population.

The parasite had not disappeared.

Use ideas about natural selection to describe how the male Blue Moon butterfly population may have returned to 40% within a year.

Classification of living organisms has changed over time.

Describe how scientific methods and theories develop over time.

The graph in Fig. 14.1 shows the level of glucose and insulin from a person with Type 2 diabetes over a four hour time period.

Write down two ways the graph in Fig. 14.1 shows that the person has Type 2 diabetes, not Type 1.

The graph in Fig. 14.2 shows the increase in Type 2 diabetes over a 10-year period.

What factor does the graph in Fig. 14.2 indicate is linked to an increase in Type 2 diabetes?

Suggest one lifestyle change that could reduce this factor and avoid a person developing Type 2 diabetes.

Water is cycled in nature.

Name one abiotic factor that affects water uptake by a plant.

Look at the diagram of the carbon cycle.

Which process is shown by arrow X in the diagram above?

Tick (✓) one box.

Which process releases carbon when organisms die ?

Tick (✓) one box.

The graph shows how carbon dioxide levels in the atmosphere have changed during the last 160 000 years.

Read this statement:

Carbon dioxide levels in the atmosphere are rising out of control.

What evidence is there in the graph for and against this statement?

Look at the section of the graph for the last 20 000 years.

What conclusions can be made about the release of carbon dioxide into the atmosphere and also its removal from the atmosphere during the last 20 000 years?

Describe how human activity has contributed to the trends in the graph and suggest how this activity could affect biodiversity.

The information in the box is part of a scientific journal report.

Growing crops with shiny leaves could cause an annual global cooling of over 0.1 °C.

This is almost 20% of the total global temperature increase since the Industrial Revolution.

Most crop plants have non-shiny leaves.

A few varieties of crop plants do have shiny leaves but they do not all produce high yields.

Explain how scientists could use selective breeding to help reduce global temperatures.