Edexcel GCSE Biology Paper 1 Higher June 2024 question paper 1BI0/1H

Which process is involved in the theory of evolution?

Figure 1 shows some stages of the theory of evolution.

overproduction variation survival of the fittest

Figure 1

State two causes of variation in organisms.

Disease is an example of a selection pressure.

Give one other example of a selection pressure that leads to survival of the fittest.

Figure 2 shows the location of the Wallace line, an imaginary line Alfred Wallace suggested, based on his research.

Wallace found that animals to the west of the line were different from animals to the east of the line.

Suggest two possible reasons why animals to the west of the Wallace line are different from animals to the east of the Wallace line.

Give one reason why the work of Alfred Wallace encouraged Charles Darwin to publish his theory of evolution.

Pepsin and trypsin are enzymes that break down proteins.

Figure 3 shows the results of an investigation into the activity of pepsin and trypsin at different pH levels.

Which molecules are produced when a protein is broken down?

Describe the trend in the graph for the enzyme pepsin.

Use data from the graph to support your answer.

State the optimum pH for the enzyme trypsin.

Explain why there is no trypsin activity at pH 5.

Temperature is a variable that should be controlled in this investigation.

Give one way the temperature could be controlled.

Malaria is a disease that causes damage to the blood and liver.

Which type of pathogen causes malaria?

State how the pathogen that causes malaria is spread.

Measles is a disease caused by a virus.

Figure 4 shows the number of measles cases reported in England and Wales from 1985 to 2015.

Explain one conclusion that can be made about the change in the number of measles cases reported from 1985 to 2015.

Describe two ways the immune system will respond to an infection by a pathogen.

Beriberi is a disease caused by a lack of vitamin B1 in the diet.

Give one reason why beriberi is classed as a non‑communicable disease.

Mendel crossed pea plants that always produced purple flowers with pea plants that always produced white flowers.

The flowers of the offspring were all purple, as shown in Figure 5.

Which conclusion can be made about the characteristic for purple flowers?

Mendel used two of the offspring with purple flowers in another cross.

The pea plants he obtained from this cross produced purple flowers or white flowers in a ratio of 3: 1.

Calculate the expected number of pea plants with purple flowers, in a sample of 160 pea plants.

A pea plant producing purple flowers had the genotype Aa.

This pea plant was crossed with a pea plant producing white flowers.

Complete the Punnett square to show the possible genotypes of the offspring.

Show the percentage of pea plants that produce white flowers in your answer.

Asexual reproduction can be used to produce flowering plants.

Give two advantages of using asexual reproduction to produce flowering plants.

Flower colour is controlled by genes.

Which is a definition of a gene?

The two strands of a DNA molecule are linked by complementary bases.

Describe how the complementary bases are linked in a DNA molecule.

A student made a microscope slide of cells taken from the inside of their mouth.

The student wore gloves while using a swab to collect cells from their mouth.

Give one other safety precaution the student should take.

A light microscope was used to obtain an image similar to the one shown in Figure 6.

(Source: © STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY)

Figure 6

Describe how the student used the light microscope to view these cells at a magnification of 400.

The cytoplasm of a cell contains a nucleus.

Explain the role of one other structure in the cytoplasm of a human cell.

DNA can be extracted from human cells in a similar way to the method used to extract DNA from fruits.

Describe the stages of the method used to extract DNA from cells.

The Human Genome Project sequenced the order of the bases in the human genome.

Give two other outcomes from the Human Genome Project.

Figure 7 shows images of two stone tools.

Scientists think that tool A was probably used by Homo erectus around 1.6 million years ago.

Tool B was probably used by Homo habilis around 2 million years ago.

Give one reason, using Figure 7, why scientists think that tool A was used by a more recent human ancestor.

Describe how scientists can date stone tools using information from where the tools were discovered.

Differences in fossilised bones indicate structural changes that have occurred during the evolution of humans.

Describe two structural changes that have occurred during human evolution.

The migration patterns of humans can be tracked by analysing DNA in mitochondria.

Figure 8 shows a mitochondrion viewed using an electron microscope.

At a magnification of 62 000 this mitochondrion has a length of 434 mm.

Calculate the actual length of this mitochondrion.

Give your answer in micrometres (µ m).

Explain why an electron microscope is used to see mitochondria clearly.

Figure 9 shows an aphid.

An aphid inserts its mouthpart into plant tissue to feed on plant sap.

(Source: http://www.biology-resources.com/drawing-aphid-wingless.html)

Figure 9

Aphids can transfer plant viruses from one plant to another.

Which term describes the role of the aphid in the transmission of plant viruses?

Describe the physical barriers of a leaf that the virus gets through when an aphid feeds.

The genetic material from the virus is transcribed by the plant cell.

Describe how mRNA is produced during transcription.

Name the stage of protein synthesis after transcription.

Biological control can be used on aphid populations feeding on crops.

Explain the advantages of using biological control on aphid populations.

Statins are a type of medicine used to treat cardiovascular disease.

Some people taking statins have reported muscle pain as a side effect.

Scientists analysed data from double‑blind trials to determine if there was a correlation between statin use and muscle pain.

In these double‑blind trials, neither doctors nor patients knew whether the patient had been given statins or not.

Describe the benefits of using double‑blind trials.

Which stage of the process for testing new medicines could involve a double‑blind trial?

In a study, people were given statins or a placebo.

The percentage of people who reported muscle pain was recorded.

Figure 10 shows the results of this study.

In year one, 9 199 people taking statins reported muscle pain.

Calculate the total number of people taking statins in this study.

Give your answer to 4 significant figures.

The scientists concluded that most of the muscle pain reported was not due to the use of statins.

Explain, using information from the table in Figure 10, why the scientists made this conclusion.

The results of the study are reliable because the data was obtained from a large sample of people.

Describe two factors that should have been considered when selecting people for the study.

When one cell goes through the stages of the cell cycle, two cells are produced.

Figure 11 shows the three stages of the cell cycle.

*(i) Describe the three stages of the cell cycle shown in Figure 11.

State what happens to the cell cycle in cancerous cells.

The production of more cells contributes to the growth of an animal.

Which other process is needed for the growth of an animal?

A parent is concerned that their child is not growing as much as other children.

Describe how a doctor might determine if the child is growing as expected.

Stomach ulcers can be caused by bacteria.

Name the bacteria that cause stomach ulcers.

People with a stomach ulcer are treated with antibiotics and an alkaline medicine to reduce symptoms.

Give a reason why the alkaline medicine is used.

Antibiotics are used to treat stomach ulcers.

Bacteria have become resistant to some antibiotics.

A scientist has an agar plate spread with the bacteria that cause stomach ulcers and discs containing different antibiotics.

Describe how the scientist could use these to determine which antibiotic can kill the bacteria.

*(c) A bacteriophage is a type of virus that can infect bacterial cells.

Figure 12 shows a bacteriophage infecting a bacterial cell.

Scientists are investigating if a bacteriophage could be used as an alternative to antibiotics.

Describe the lytic lifecycle of a virus and suggest why a bacteriophage could be used as an alternative to antibiotics.