Why would gene therapy fail to cure illnesses caused by bacteria? Gene therapy reduces symptoms but never cures illnesses.
Gene therapy does not work on most people.
Gene therapy only focuses on replacing mutated genes.
Gene therapy is too long a process

Option A

Explanation:

The heterozygous allele can be defined as the condition in which the organism has two different alleles of the gene.

It is represented as Rr, means a capital letter and a small letter. This hows that the organism has one dominant gene and one recessive gene in it.

This dominant and recessive condition decides the genotype and phenotype of organism.