Parents give their offspring two versions of each gene, or two alleles. If the alleles are different, only one of the alleles will be expressed. It would be the dominant allele. The one with the masked effect would be the recessive gene. Genes that prevent the other gene from "showing" are dominant. Dominant genes are represented by uppercase letters. Genes that do not "show" even though they are present are recessive. If both alleles are recessive, the recessive phenotype is expressed. Recessive alleles are represented by lowercase letters.
- Both genes of a pair are the same - homozygous or purebred.
- TT - homozygous- dominant
- tt - homozygous- recessive
- One dominant and one recessive gene - heterozygous or hybrid.
- Tt - heterozygous
|
|