OCR GCSE Biology A (Gateway) Paper 2 Foundation June 2023 question paper J247/02

Which process in the carbon cycle decreases the amount of carbon dioxide in the air?

A Combustion

B Decomposition

C Photosynthesis

D Respiration

Your answer

Which of these is a biotic factor that can affect the growth of plants?

A Carbon dioxide levels

B Light availability

C Mineral content of the soil

D Number of primary consumers

Your answer

A genetic disorder is caused by a dominant allele (D). The recessive allele is (d).

Which row shows all the possible genotypes for heterozygous and homozygous individuals?

Your answer

Which sentence is a correct description of a chromosome?

A A length of protein that contains the genetic material.

B A long molecule of DNA that contains genes.

C A part of a gene that codes for a particular protein.

D A strand of DNA that can leave the nucleus.

Your answer

What does the lining of the trachea (windpipe) produce to defend the body against pathogens?

A Acid

B Antigen

C Enzymes

D Mucus

Your answer

There are 28 chromosomes in each elephant sperm cell.

What is the diploid number of chromosomes in elephants?

A 14

B 28

C 56

D 112

Your answer

Charles Darwin and Gregor Mendel did important work in the development of science.

Which row gives the areas of their work?

Your answer

Ecotourism can cause benefits and problems for conservation.

Which row gives a benefit and a problem caused by ecotourism?

Your answer

When a drug is developed to treat a disease, the drug is tested.

What is the final stage in this testing?

A Testing on animals to see if it is safe.

B Testing on animals to work out the correct dose.

C Testing on healthy people to see if it has side effects.

D Testing on people with the disease to see if it is effective.

Your answer

The cuticle on plant leaves helps to prevent pathogens entering the plant.

Which statement describes how the cuticle does this?

A Acts as a physical barrier

B Engulfs microbes

C Produces antimicrobial substances

D Releases antibodies

Your answer

Antibiotics can be tested on bacteria growing on a Petri dish.

The clear area around an antibiotic disc gives information about how effective the antibiotic is.

What is the closest estimate of the clear area on this Petri dish?

(Include the disc and use the formula: Area = r² where = 3)

3 cm² A

4 cm² B

6 cm² C

12 cm² D

Your answer

Which statement describes why seeds from seedbanks are an important tool in conservation?

A If there is a food shortage then the seeds can be used for food.

B The seeds can be used if certain species of plants become extinct.

C The seeds can be used to feed endangered animals.

D The seeds grow fast as the temperature is warm inside the seedbank.

Your answer

Which group will have the most organisms in any ecosystem?

A Community

B Population

C Species

D Trophic level

Your answer

Biomass is lost as it passes through a food chain.

Which processes are responsible for this loss in biomass?

A Egestion, excretion and respiration

B Egestion, transpiration and respiration

C Excretion, transpiration and respiration

D Photosynthesis, egestion and excretion

Your answer

Sorghum is a crop plant grown in Africa for its seeds as shown in Fig. 16.1.

Fig. 16.1

Weaver birds are a major problem for farmers who grow sorghum.

One weaver bird can eat 15 g of sorghum seeds in a day. A large colony of weaver birds has 5 000 000 birds.

Calculate the mass of seeds in kilograms that this colony eats in a day.

Sorghum produces a bitter chemical in its seeds. This makes the seeds less likely to be eaten by birds.

Complete each sentence about how the bitter chemical was first made by sorghum. Use the words from the list.

gene meiosis mutation pathogen sugar

The bitter chemical was first made due to a change in a........

This type of change is called a........

Farmers have developed varieties of sorghum with lower levels of the bitter chemical.

To do this they:

• chose two plants with less bitter chemical than other plants

• bred these plants together

• repeated the same steps with the offspring.

What is the name of this process?

Scientists recorded the percentage of sorghum grown with high levels of bitter chemical in different areas of Africa. They also recorded the number of weaver birds living in the same areas.

The graph shows the data they collected.

In some areas, there are low numbers of weaver birds.

Which area of Africa, west, east or south, has the least number of weaver birds that eat sorghum?

Complete the sentence about the graph.

In the areas with low numbers of weaver birds, farmers choose to grow

a lower / a higher / the same percentage of sorghum with high levels of

bitter chemicals.

Give a reason why the farmers make this choice.

The table shows the mean mass of four types of rodent and the mean number of years they live.

Plot the data from the table on the graph.

Draw a line of best fit through the points.

Mole rats are rodents that have a mean mass of 60 g.

Use your graph to predict the mean number of years that mole rats live.

Mole rats actually live much longer than predicted by the graph.

Scientists think that one reason for this is that their cells do not divide in an uncontrolled way.

Explain why this would help the mole rats to live longer.

For each of these questions choose your answers from the types of hepatitis shown in the table.

List all the types of hepatitis that can be treated using antiviral tablets.

Which type of hepatitis can be prevented by regular hand washing?

Which type of hepatitis is a non-communicable disease?

Which type of hepatitis involves interaction between two different diseases?

Explain why hepatitis A cannot be treated using antibiotics. Use information from the table.

Complete each sentence to explain why a person cannot develop hepatitis A or B twice.

Use the words from the list.

antibiotics antibodies antigens immune

red blood vaccinated white blood

On the surface of the viruses there are molecules called........

These molecules are detected by........ cells.

These cells produce protein molecules called........ which attack the viruses.

If the person gets infected again, the protein molecules will destroy the viruses before they can make the person ill.

The person is said to be........

Describe how scientists could estimate the number of one type of plant in a habitat.

Duckweed is a small plant that floats on the surface of ponds.

Each plant has one leaf and it usually reproduces by dividing into two.

Only occasionally does it reproduce sexually by growing flowers.

In the box next to each statement, put A if it applies to asexual reproduction or S if it applies to sexual reproduction.

A student investigates the effect of acid rain on the reproduction rate of duckweed.

This is the student’s method:

• Put pondwater with a pH of 4.5 in four different beakers.

• Add five duckweed plants to each beaker.

• Repeat this with beakers containing pondwater at pH 6.5 and 8.5.

• Leave the beakers for 10 days in the same conditions.

• After 10 days count how many duckweed plants are in each beaker.

The table shows the student’s results.

What is the independent variable in this investigation?

Identify the pH of the pondwater where the mean number of duckweed plants is the same as the mode for the four beakers.

Tick (✓) one box.

The student thinks that there is a problem with their data at pH 8.5. This resulted in the mean being inaccurate.

Explain how the student could improve their investigation to get a more accurate result for the mean.

The student concluded that acid pollution slows the rate of duckweed reproduction.

Explain how acid pollution slows the rate of duckweed reproduction.

Use ideas about enzymes and photosynthesis in your answer.

The student also concluded that pH 6.5 is the best pH for duckweed reproduction.

The student’s teacher says that they need to extend the experiment to be sure of this.

Describe how the student should extend their experiment.

The demand for food in the world is growing but there are risks to the supply of food.

There are methods that can be used to reduce these risks.

Draw lines to connect each risk with the correct method used to reduce the risk.

One line has been drawn for you.

Risk
Method used to reduce the risk

Many people in the world eat fish as their main source of protein.

Wild fish: caught from the sea Aquaculture: fish grown in large tanks in lakes or the sea

The graph shows how the total demand for fish has changed since 1950 and how it is expected to change up to 2050. It also shows how the total demand is met by the supply of wild fish and fish from aquaculture.

Use the graph to complete each sentence about the demand for fish.

The total demand for fish is expected to increase from 20 million tonnes in 1950 to

80 / 140 / 220 million tonnes in 2050.

In 2050, the percentage of all fish supplied by wild fish is expected to be about

36% / 57% / 64%.

Scientists are using genetic engineering to increase the mass of Atlantic salmon produced by aquaculture. Chinook salmon are fish that grow fast.

The diagram shows how scientists are producing genetically engineered Atlantic salmon.

Genetically engineered Atlantic salmon

Describe how scientists can increase the mass of Atlantic salmon using genetic engineering.

In 2020 some salmon escaped into the sea from a tank used in aquaculture.

Suggest why this problem makes some people concerned about producing genetically engineered salmon.

Complete each sentence about decomposition.

Decomposition is caused by microorganisms such as........

The microorganisms use the process of........ to release the energy in dead organisms.

Decomposition also allows minerals to be........ in nature for plants to use.

Some students investigate plant decomposition. They put three different plant wastes into compost heaps. Each type of plant waste contains different ratios of carbon to nitrogen.

They measure the rate of decomposition by measuring the temperature in the compost.

The graph shows their results.

Time after compost heap is set up (days)

The pupils used the temperature of the compost heap as a measure of the rate of decomposition.

Which statement explains why they could do this?

Tick (✓) one box.

Which statement describes the results of the investigation?

Tick (✓) one box.

The higher the nitrogen content compared to carbon, the faster the rate of decomposition.

Give one abiotic factor that the students should keep constant in their experiment.

The table shows the mass of carbon and nitrogen in different plant materials.

Which plant material would decompose the fastest?

Explain your answer using calculations and the graph in (b).

Plant material........

Reason........

A doctor makes this statement: The allele causing Gillespie syndrome in this family is recessive.

Explain why this statement is correct. Use evidence from Fig. 23.1.

Person A and person B are expecting another baby.

Complete Fig. 23.2 to find the probability that it will have Gillespie syndrome.

(Use G for the dominant allele and g for the recessive allele.)

Fig. 23.2

Person D is very sensitive to bright light and has difficulty controlling their balance.

Explain why this is.