Question

Difference between heterozygous and homozygous

Answer 1

If a mutation occurs in just one copy of the gene then that individual is considered heterozygous. On the other hand if both copies of a gene are mutated then that individual is homozygous genotype.

Answer 2

ANSWER :-

The differences between Heterozygous and Homozygous genotypic combinations are as follows-

Heterozygous :-

• Heterozygous combinations of genes constitute of genotypes that are made up of a mixture of both, wild, original, non mutated, dominant genes, and mutated, recessive genes.
• Heterozygous combinations are found in the progeny that are produced as a result of impure breeding or genetic crossing of pure-line parents.
• Only the wild, original, non mutated, dominant allele is able to express itself in phenotypes of such genotypic combinations.
• Examples of heterozygous combinations are as follows-

1. In the context of height, Tt (Heterozygous tall), heterozygous combinations can never produce dwarf plants as a phenotype.
2. In the context of eye colour Bb (Brown eyes), heterozygous combinations can never produce blue eyes as a phenotype.

Homozygous :-

• Homozygous combinations of genes constitute genotypes that are made up of wild, original, non mutated, dominant genes only.
• Homozygous combinations are found in the progeny that are produced as a result of pure breeding or true breeding or genetic selfing of pure-line parents.
• The progeny produced through pure breeding are referred to as "Pure-line individuals".
• Examples of homozygous combinations are as follows-

1. In the context of height, TT (Homozygous tall) and tt (Homozygous dwarf).
2. In the context of colour of flowers, RR (Homozygous red) WW (Homozygous white).