PATHOLOGY

PATHOLOGY MCQ

GENETICS AND DISEASE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
A carrier is a person who has
A
one recessive and one dominant allele for a trait
B
two recessive alleles for a trait
C
two dominant alleles for a trait
D
more than two alleles for a trait
Explanation: 

Detailed explanation-1: -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-2: -A carrier has a gene mutation on the recessive gene. The dominant gene outweighs the recessive gene, so while a carrier does not develop the disease, a carrier can pass on the gene with a mutation to his or her child.

Detailed explanation-3: -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-4: -A carrier, as related to genetics, is an individual who “carries” and can pass on to its offspring a genomic variant (allele) associated with a disease (or trait) that is inherited in an autosomal recessive or sex-linked manner, and who does not show symptoms of that disease (or features of that trait).

Detailed explanation-5: -Thus, a person cannot be a carrier for a dominant genetic disorder.

There is 1 question to complete.