What is an allele?

  1. In the nucleus of the cell, there are pairs of chromosomes which carry the same genes in the same places. 2) Alleles are different versions of these genes.3) For example, a person may have an allele for brown eyes on one chromosome and an allele for green eyes on the other. 4) Dominant alleles only require one copy for it to be expressed, whereas recessive alleles need two copies: they are only expressed if both alleles are recessive (no dominant alleles). 
ES
Answered by Ella S. Biology tutor

7912 Views

See similar Biology GCSE tutors

Related Biology GCSE answers

All answers ▸

What is the difference between an animal cell and a plant cell?


In which cell structures does respiration mainly occur?


What is eutrophication? Explain how this process can cause harm to the environment, particularly when farmers apply fertiliser to their land.


Why does the breathing rate not return to normal after vigorous exercise?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning