Gene
Contents
Key Stage 3
Meaning
A gene is a small unit of DNA that provides instructions for a specific feature of an organism.
About Genes
- There is a gene that controls eye colour with a different version of the gene for each colour.
- There is a gene that controls whether a person has a widow's peak or not.
- There are a number of genes that control the colour of a person's skin or the shape of their nose.
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| An eye colour gene controls the colour of a person's eyes. | There are several genes that determine the number of spots on a dalmatian. | The shape of bird's beak is caused by a number of genes working together. | A "widow's peak" is controlled by a particular gene. |
Key Stage 4
Meaning
A gene is a small unit of DNA that provides instructions for a specific feature of an organism.
About Genes
- There can be several alleles of the same gene. A human will inherit one allele of a gene from their mother and another allele of a gene from their father.
- Only some characteristics are coded for by one gene. Most characteristics are controlled by a large number of genes in the genome.
Genes can be divided into two categories:
- Coding DNA - Genes which are 'expressed' which means used as the templates for protein synthesis.
- Non-coding DNA - Genes which affect whether other genes will be expressed. These genes are said to 'turn off' parts of the DNA and can respond to environmental changes.
References
AQA
- Gene, pages 24-2, 32, 236-9, 300-1, 304-5, 308-9, GCSE Biology; Student Book, Collins, AQA
- Genes, pages 15, 66, GCSE Combined Science; The Revision Guide, CGP, AQA
- Genes, pages 15, 84, GCSE Biology; The Revision Guide, CGP, AQA
- Genes, pages 19,183-4, GCSE Biology, Hodder, AQA
- Genes, pages 19-20, GCSE Combined Science Trilogy 1, Hodder, AQA
- Genes, pages 34, 204, 217, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Genes, pages 34, 244, 265, GCSE Biology, CGP, AQA
- Genes, pages 34, GCSE Combined Science Trilogy 2, Hodder, AQA
- Genes, pages 6,8, 26-27, 199, 206-213, 224-225, 227, 230-231, 234-235, GCSE Biology; Third Edition, Oxford University Press, AQA
Edexcel
- Genes, page 27, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Genes, pages 34, 35, GCSE Biology; The Revision Guide, CGP, Edexcel
- Genes, pages 40, 63, GCSE Combined Science, Pearson Edexcel
- Genes, pages 52, 85, GCSE Biology, Pearson, Edexcel
- Genes, pages 89, 93, GCSE Biology, CGP, Edexcel