- when both alleles are recessive the individual is described as being homozygous recessive for that gene outcome.
- when there is one dominant and one recessive allele, the individual is described as being heterozygous for that gene outcome.
- in genetic diagrams we use letters to simplify words e.g for earlobes combinations e and E are used. these are called genotypes.
- the physical charateristic displayed by the idividual are called phonotypes.e.g attatched earlobes.
- in genotypes, we use a capital letter to represent the dominant allele and a lower case to show the recessive.
- inherited or genetic disorders like sickle cell disease and cystic fibrosis are caused by 'faulty' alleles.
- when an individual has two dominant alleles, they are describes as being homozygous dominant for that gene.
- punnett squares show a way of showing simple genetic relationships