NEET BIOLOGY

Detailed explanation-1: -Recessive inheritance means both genes in a pair must be abnormal to cause disease. People with only one defective gene in the pair are called carriers. These people are most often not affected with the condition. However, they can pass the abnormal gene to their children.

Detailed explanation-2: -Recessive alleles are only expressed if both of a person’s alleles are recessive. If a person has one dominant allele and one recessive, he is called a carrier. This is because he expresses the dominant trait, but “carries” the recessive trait. An example of this is albinism.

Detailed explanation-3: -An individual with one dominant and one recessive allele for a gene will have the dominant phenotype. They are generally considered “carriers” of the recessive allele: the recessive allele is there, but the recessive phenotype is not.

Detailed explanation-4: -Option c is correct because recessive traits will be observed only when the individuals are homozygous for that trait because for the recessive traits to appear, there should be two recessive alleles (homozygous) otherwise dominant alleles in heterozygous will show dominant traits.

Detailed explanation-5: -Recessive alleles only show their effect if the individual has two copies of the allele (also known as being homozygous?). For example, the allele for blue eyes is recessive, therefore to have blue eyes you need to have two copies of the ‘blue eye’ allele.