Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

Lethal recessive mutations are perpetuated by the reproduction of carriers with normal what?

1. Genotypes

2. Phenotypes

3. Karyotypes

4. Alleles

The correct answer is: Phenotypes

Lethal recessive mutations are carried by individuals who possess one normal allele and one mutated allele, meaning they do not express the lethal condition due to the presence of the normal allele. These individuals are referred to as carriers. The term "phenotype" specifically refers to the observable characteristics or traits of an individual, which are influenced by their genotype. In this context, carriers of lethal recessive mutations exhibit a normal phenotype because the normal allele compensates for the lethal mutation, allowing them to survive and reproduce. This phenomenon ensures that the lethal recessive allele can continue to be passed on to the next generation when these carriers mate with individuals who also have normal phenotypes. This understanding emphasizes the importance of the visible traits exhibited by organisms (phenotypes) in the context of genetic mutations and inheritance. In contrast, genotypes refer to the genetic makeup, karyotypes refer to the complete set of chromosomes, and alleles are the different versions of a gene, but these terms do not capture the essence of how lethal recessive mutations persist through carrier reproduction specifically concerning observable traits.