The Human Genome Project

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In short

The Human Genome Project was an international project, completed in 2003, that identified the sequence of bases in human DNA and where the genes are. It can help find genes linked to inherited disorders and develop new treatments tailored to a person's genes. Concerns include worry about incurable diseases and keeping genetic information private.

The Human Genome Project was an international research project to map the human genome. It was completed in 2003 and identified the sequence of bases in human DNA and where the genes are.

Potential applications in medicine

Finding the genes linked to inherited disorders, so that people at risk can be tested and their risk predicted.
Developing new treatments and drugs, and tailoring treatment to a person's own genes.
Understanding how genes are involved in disease, which could help prevent or diagnose it earlier.

Concerns

People may not want to know if they are likely to develop a disease that cannot be cured, which could cause worry.
Genetic information must be kept private. There are concerns that it could be used unfairly, for example by insurers or employers.

Exam tip:

A 'discuss' question wants a balanced answer. Give at least one benefit and one concern, and link each to the genome information.

Quick check

State where genetic variation in a population comes from.
Show answer
Mutations (and sexual reproduction).
What is environmental variation?
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Different characteristics caused by an organism's environment (acquired characteristics).
What effect do most mutations have on the phenotype?
Show answer
No effect.
Give one possible medical use of the Human Genome Project.
Show answer
For example, identifying genes linked to inherited disorders so that people can be tested, or developing treatments.

Written and checked against the Edexcel GCSE Combined Science (1SC0) specification · Updated October 2026

Frequently asked questions

What causes variation in a species?

Variation is caused by genes, the environment, or a combination of both. Genetic variation comes from mutation and sexual reproduction, which give individuals different alleles, as with eye colour. Environmental variation is caused by conditions during life, such as diet, climate or injury; for example, plant height can be affected by light.

What is the difference between continuous and discontinuous variation?

In continuous variation, a feature can take any value within a range, such as height or mass, and the results are shown on a histogram. In discontinuous variation, a feature falls into distinct categories with nothing in between, such as sex or flower colour, and the results are shown on a bar chart.

Are all mutations harmful?

No, most mutations are not harmful. A mutation is a change in the base sequence of DNA, and most mutations have no effect on the phenotype. Some have a small effect, and only rarely does a single mutation significantly affect the phenotype. Mutations are the source of genetic variation within a population.

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