Edexcel GCSE Combined Science Paper 1: Biology 1 Higher June 2025 question paper 1SC0/1BH

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 1 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 2 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 3 shows some information about each cube.

Calculate the volume of cube C.

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

A report stated that Homo habilis was a hominin species that lived on Earth between 2.4 million years ago and 1.5 million years ago.

State the number of years that Homo habilis lived on Earth.

Fossil evidence suggests that Homo habilis used tools.

State one use of these tools.

Scientists use fossil discoveries to suggest the structure of the whole body.

Lucy is a fossil of the species Australopithecus afarensis.

Describe how the body structure suggested for Australopithecus afarensis is different from the body structure suggested for Homo habilis.

Explain what could have caused the extinction of Australopithecus afarensis.

Figure 4 shows how the three-domain classification system was developed.

Describe the differences between prokaryotes and eukaryotes and why the three domain classification system was introduced.

The pathogen Vibrio cholerae causes the disease cholera.

Figure 5 shows Vibrio cholerae bacteria.

Complete the table to show the function of structure P and structure Q.

On the original image, the length of one bacterial cell is 12 mm.

The actual length of this bacterial cell is 2.0 µ m.

Calculate the magnification.

State one symptom of the disease caused by Vibrio cholerae.

State how the disease caused by Vibrio cholerae is transmitted.

Describe the specific immune response when a pathogen infects the body.

Reaction time can be tested by dropping a ruler and measuring the distance it travels before it is caught.

Figure 6 shows how the test works.

This method was used to test the reaction times of three students.

Each student completed the test five times and the distances were recorded.

State how the median distance for each student could be determined from the results.

State and explain one variable that needs to be controlled in this investigation.

Figure 7 shows the results recorded for the three students.

Explain one conclusion that can be made from the results in Figure 7.

A student wanted to investigate the effect of two different drinks containing caffeine on reaction time using this method.

Devise a plan the student could use.

Figure 8 shows a myelinated sensory neurone.

Identify structure Z.

Figure 9 shows how the diameter of neurones affects the speed of electrical impulses.

Comment on how the diameter of a neurone affects the speed of the electrical impulses.

Genetic disorders can be caused by mutations in the DNA of genes.

Cystic fibrosis is a recessive genetic disorder.

Figure 10 shows a family pedigree for the inheritance of cystic fibrosis.

Which row is correct for the mother, father and son?

Cystic fibrosis causes the build‑up of thick, sticky mucus.

Describe how the build-up of thick, sticky mucus affects the airways of a person.

Huntington’s disease is a condition caused by a dominant allele.

Explain the phenotypes of the offspring of a genetic cross between a person who is heterozygous for the Huntington’s allele and a person who is not affected.

Use the Punnett square as part of your answer.

*(c) Explain how DNA is extracted from strawberries.

Include in your answer:

• the reasons for each stage of the extraction process

• the structure of a DNA molecule.