WAEC Agriculture 2014 Paper

Concept:A heterozygous plant crossed with a homozygous dominant plant yields half homozygous dominant and half heterozygous offspring.Explanation:Let the heterozygous parent be $Aa$. Let the homozygous dominant parent be $AA$.Gametes produced by $Aa$ are $A$ and $a$. Gametes produced by $AA$ is $A$.Possible offspring genotypes are $AA$ and $Aa$. The cross gives $Aa$ in 2 out of 4 possible combinations.Thus, the proportion of heterozygous offspring is $\frac{2}{4} = \frac{1}{2}$. This equals 50% heterozygous.Answer:50% heterozygous.