Edexcel GCSE Combined Science Paper 1: Biology 1 Foundation June 2025 question paper 1SC0/1BF

Genes control natural hair colour in humans.

Which term describes the differences in hair colour?

Genes are found on chromosomes.

Name the part of the human cell where chromosomes are found.

The hair colour of 24 students was recorded.

Figure 1 shows the results.

Complete Figure 2 to show the tally and the total for brown hair.

Complete the bar chart to show the totals in Figure 2 and label the x ‑axis.

Figure 3 shows a sperm cell.

Name the part labelled R.

Draw one straight line from each part of the sperm cell to its function.

Animal cells and plants cells are both eukaryotic cells.

State one structure found in a plant cell that is not found in an animal cell.

DNA is found in cells.

Figure 4 shows part of a DNA molecule.

Which type of large molecule is DNA?

Describe how the bases of a DNA molecule are held together.

Figure 5 shows the times when Homo sapiens (modern humans) and some of their ancestors are thought to have lived.

Which term is used to describe changes in species over time?

Estimate the length of time Homo habilis is thought to have lived on Earth.

_........ million years

Describe two methods scientists used to date the fossils of Ardi or Lucy, as shown in Figure 5.

The ancestors of modern humans used selective breeding to improve the plants they used for food.

Complete the sentences using words from the box.

Selective breeding involves choosing parents with

desirable_........ .

The best offspring are bred together and this process is repeated over

many_........ .

Suggest one feature of a banana that could be improved by selective breeding.

The DNA of fruit can be modified to produce new varieties.

Figure 6 shows part of a method used to extract DNA from fruit.

State the purpose of both step 1 and step 2.

step 1_........

State why the cold ethanol was added in step 3.

A scientist uses the method shown in Figure 7 to investigate the reaction times of some students.

Which measurement should be recorded to compare reaction times?

Figure 8 shows the results of five students.

Which is the mean of the results in Figure 8?

Explain which of the five students had the slowest reaction time.

Give two variables that need to be controlled during this investigation.

Figure 9 shows a motor neurone.

State the role of a motor neurone in a reflex arc.

Explain the function of the myelin sheath.

Describe how a nerve impulse passes across the gap between two neurones.

Figure 10 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.

_........ cases

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 11 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.

Figure 12 shows a beaker containing a potato cylinder in distilled water.

Explain why the mass of this potato cylinder will change when it is placed in distilled water.

A scientist investigated the rate of diffusion using three agar cubes of different sizes.

Each cube contained a pH indicator that changed from pink to colourless when placed in acid.

The cubes were placed in a beaker containing an acid.

Figure 13 shows some information about each cube.

Calculate the volume of cube C.

_........ cm³

Explain the difference in the times taken for cubes A and B to become colourless.

* (c) Liquid agar was poured into a Petri dish and allowed to set.

A well was cut in the centre of the set agar.

Kiwi fruit juice was poured into the well.

Kiwi fruit juice contains an enzyme that causes set agar to break down into a liquid.

Figure 14 shows the results after 30 minutes.

Devise a plan to investigate the effect of different concentrations of kiwi fruit juice on the breakdown of set agar, using the equipment shown in Figure 14.

Your plan should include:

• measurements that need to be taken

• variables that need to be controlled.