Key Stage 4
Meaning
Alleles are different forms of the same gene.
About Alleles
- A single gene, such as the gene for eye colour, may have several alleles such as blue eyes, brown eyes, green eyes...etc.
- Alleles can be dominant or recessive.
- Dominant alleles are expressed in the phenotype when there is only one copy of the allele. Whereas recessive alleles are only expressed in the phenotype when there are two copies.
References
AQA
- Allele, pages 254-7, GCSE Biology; Student Book, Collins, AQA'
- Alleles, page 217, GCSE Combined Science Trilogy; Biology, CGP, AQA'
- Alleles, page 265, GCSE Biology, CGP, AQA'
- Alleles, page 70, GCSE Combined Science; The Revision Guide, CGP, AQA'
- Alleles, page 91, GCSE Biology; The Revision Guide, CGP, AQA'
- Alleles, pages 199, 208-213, 234-235, GCSE Biology; Third Edition, Oxford University Press, AQA'
- Alleles, pages 35, GCSE Combined Science Trilogy 2, Hodder, AQA'
Edexcel
- Alleles, page 101, GCSE Biology, CGP, Edexcel
- Alleles, pages 28-30, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Alleles, pages 38-42, GCSE Biology; The Revision Guide, CGP, Edexcel
- Alleles, pages 46-47, 64, GCSE Combined Science, Pearson Edexcel
- Alleles, pages 61, 64-65, 88, GCSE Biology, Pearson, Edexcel
- Alleles; codominant, page 68, GCSE Biology, Pearson, Edexcel
- Alleles; multiple and missing, pages 68-69, GCSE Biology, Pearson, Edexcel