Question

Homozygous dominant x heterozygous?

Answer 1

By a cross between homozygous dominant and heterozygous. `50%` of the offsprings will be dominant homozygous and `50%` heterozygous.

Explanation:

The answer can be easily explained by taking a specific example of pea plant, considering trait height, in which tallness is dominant allele and dwarfness is recessive allele.

A homozygous tall pea `("TT")` plant is crossed to heterozygous tall `("Tt")` plant. All the gametes produced by homozygous `("TT)"` plant will carry the `"T"` allele and gametes produced by heterozygous tall `("Tt")` plant will produce `50%` gametes that carry the `"T"` allele and 50% gametes carrying the `"t"` allele.

Each gamete produced by homozygous tall plant has equal chance to fuse with gamete carrying the `"T"` allele or `"t"` allele produced by the heterozygous tall plant.

Random and chance fusion between gametes produced by homozygous tall and heterozygous tall plants will produce approximately `50%` homozygous tall offspring plants and `50%` heterozygous tall offspring plants.