WAEC Agriculture 2020 Paper

Concept:A gene that expresses its effect in both homozygous and heterozygous forms is regarded as a dominant gene.Explanation:Consider a heterozygous individual with alleles $Tt$.The dominant allele $T$ appears in the phenotype, while the recessive allele $t$ is masked.A recessive allele is expressed only in the homozygous condition, for example $tt$.Thus, expression in both homozygous form ($TT$) and heterozygous form ($Tt$) is a characteristic of dominance.The given options do not include the term “dominant gene”.So none of the options A–D correctly answers the question.Answer:Dominant gene; none of the options (A–D) is correct.