OCR GCSE Biology B (21st Century) Breadth in Biology Foundation June 2023 question paper J257/01

Write these structures in order of size.

Cell Chromosome Gene Nucleotide Nucleus

Smallest........

Largest........

The table shows the number of chromosomes that different animals have in each body cell.

A student looks at the data and writes this conclusion:

Explain why the student is not correct.

Use two pieces of evidence from the table to support your answer.

Cocker spaniels are a breed of dog. The colour of their fur is affected by the alleles of one of their genes.

The black fur allele (B) is dominant. The brown fur allele (b) is recessive.

Two cocker spaniels have a puppy.

• One of the parents has black fur and the alleles Bb.

• The other parent has brown fur and the alleles bb.

Calculate the probability that the puppy has black fur, using the Punnett square.

Complete the sentence to explain why many other fur colours and patterns are seen in cocker spaniels.

Many different fur colours and patterns are seen in cocker spaniels because most features

are the result of no genes / one gene / many genes.

Horses can develop a condition called laminitis.

The graph shows the number of laminitis cases in one area in one year.

Complete the sentence.

A horse is most likely to develop laminitis in the month of........

How many cases of laminitis were there in February?

Plants can defend themselves against disease.

Which two describe plant defences against disease?

Tick (✓) two boxes.

Ash dieback is a plant disease caused by a pathogen found in soil. It is easily spread from one tree to another.

A boy goes cycling in a woodland where there is ash dieback.

Suggest one way in which the boy could prevent spreading the disease to another woodland.

Which type of pathogen causes ash dieback?

Tick (✓) one box.

A scientist collects a sample of pathogen cells from a plant with a disease.

The scientist uses different techniques to try to work out how the disease can be treated.

Draw one line from each technique to the correct reason it is used.

One has been done for you.

Complete the sentences to describe the process of photosynthesis.

Use words from the list.

carbon dioxide chloroplast glucose

hydrogen oxygen water

In the first stage of photosynthesis light and chlorophyll are needed to split

........ molecules into hydrogen and oxygen.

The........ is released to the atmosphere as a waste product.

The........ is transferred to the second stage where it combines with

........ to form glucose.

The glucose produced by plants can be stored as a large carbohydrate.

What is the name of this carbohydrate?

Tick (✓) one box.

The diagram shows how carbon moves through parts of the carbon cycle.

Explain why photosynthesis in producers is important for consumers.

Explain why cellular respiration in consumers is important for producers.

Some trees lose their leaves in autumn. These leaves fall to the ground and decay.

A student investigates the rate of decay of leaves. The table shows the results.

Calculate the rate of decay.

When a person swims in the sea and their body is surrounded by water, they are at risk of hypothermia.

Hypothermia is where body temperature falls below 35 °C.

A student investigates the effect of different water temperatures on the temperature of the body.

The student uses a test tube of red liquid at 37 °C to represent the human body.

Describe a method the student could use to investigate the effect that the surrounding water temperature has on the temperature of the red liquid in the test tube.

In your method describe:

• what the student should change

• what the student should measure.

Describe one thing the student should control in the method described in (a)(i).

Why is a test tube of liquid not a good model of the human body?

The amount of water in the body should be kept constant.

The table shows the amounts of water gained and lost from one person in one day.

Calculate the volume of water needed to be lost in urine to maintain the water balance of the person’s body.

Complete the sentences to explain why it is important to control the amount of water in the blood.

Use words from the list.

active transport burst diffusion fully

osmosis partially shrink

The cell membranes of human body cells are........ permeable.

If there is too much water in the blood, water will enter the cells by........

This may cause the cells to........

Humans sweat when they are hot. Sweat contains water.

Some people have a condition that makes them produce too much sweat. A chemical called Botox can be used to treat this condition.

Botox stops the functioning of neurons that usually send nerve impulses to glands and muscles.

Which type of neuron is affected by Botox?

Tick (✓) one box.

Suggest why some people may be concerned about using Botox to treat their condition.

Botox is a protein.

Describe a test you could use to show that Botox is a protein.

The table shows the length of the menstrual cycle for seven different females.

Calculate the mean menstrual cycle length.

Give your answer to the nearest whole number.

Mean menstrual cycle length........ days

Calculate the median menstrual cycle length.

Median menstrual cycle length........ days

Sometimes ovulation does not occur and the menstrual cycle finishes early.

Which female in the table may not have ovulated?

Explain your answer.

Female........

Explanation........

What is the role of hormones in sexual reproduction in humans?

Complete the table to describe different types of contraception.

Tick (✓) the correct boxes in each row.

Complete the sentences about meiosis.

Use words from the list.

double gametes growth half

interphase one three two

Meiosis is a type of cell division that produces........

During meiosis the chromosomes are copied in a stage called........

This stage is followed by........ cell divisions which results in genetically

different cells with........ the number of chromosomes.

Yellow fever is a disease caused by a virus.

A person is vaccinated against yellow fever. The graph shows the results of tests from this

Explain how the vaccination caused this person’s body to make antibodies against yellow fever.

Suggest why the number of antibodies has not returned to zero, 1000 days after vaccination.

What is the minimum number of days after vaccination that somebody should wait before travelling to an area where yellow fever is common?

Explain your answer.

Number of days........

Explanation........

The yellow fever virus is carried by mosquitoes.

Suggest two ways, other than vaccination, to prevent the spread of yellow fever.

Why do we need to vaccinate a large proportion of the population to stop the spread of a disease?

Cancer is a different type of disease.

Which statements about cancer are true, and which are false ?

Tick (✓) one box in each row.

True False

Complete the table to compare cellular aerobic and anaerobic respiration in humans.

Tick (✓) the correct boxes in each row.

Which statement about respiration is correct?

Tick (✓) one box.

Heart muscle contains approximately 5000 mitochondria in every cell.

Suggest why heart muscle cells need so many mitochondria.

The image shows the mitochondria in a section of heart muscle. The mitochondria are different sizes.

One of the mitochondria is labelled.

Estimate the number of mitochondria in this image.

The table shows the percentage of land covered in rainforest in a country.

Describe the trend in the data.

The government of the country started to protect areas of the rainforest and even paid people to regrow it.

Suggest when the government started to do this.

Predict when the rainforest will reach the percentage land coverage seen in 1940, if it increases by the same rate as shown from 1997 to 2005.

A rainforest is one of the most biodiverse areas of the Earth.

Suggest why the government wants to continue to regrow the rainforest.

Suggest two challenges of regrowing the rainforest.

Some plants in the rainforest reproduce sexually, but others reproduce asexually.

Which statements describe sexual reproduction, and which describe asexual reproduction?

Tick (✓) one box in each row.