Question

carrier organism refers to an individual,which carries a

Answer 1

guest that refers to bacteria or virus or anything of that kind

Answer 2

Complete Question:

A Carrier organism refers to an individual, which carries

a. a recessive gene that is not expressed

b. a dominant gene that is not expressed

c. a recessive gene that is expressed

d. a dominant gene which is expressed

Answer:

A Carrier organism refers to an individual, which carries a recessive gene that is not expressed.

Explanation:

• According to Mendel's law of dominance, a dominant allele dominates the other allele and expresses. Hence options b. & d. are discarded since both are irrelevant in this context.

• A recessive gene expresses itself only when it is in a homozygous state, hence option c. is incorrect since it cannot act as a carrier.

• In classical genetics, a carrier refers to an individual who “carries” and can pass on to the next generation 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 express any symptoms of that disease (or features of that diseased trait).

• Thus carrier organism is an individual who carries one deleterious allele for an autosomal recessive disorder (predisposes to disease).

• An individual or other organism that has inherited a recessive allele for a genetic trait or mutation but does not display that trait or show symptoms of the disease.

• A carrier organism carries two different forms (alleles) of a recessive gene (alleles of a gene linked to a recessive trait) and is thus heterozygous for that recessive gene.

• Although carriers convey and maintain recessive genes within a population by passing them on to offspring, they themselves are not affected by the recessive trait associated with the recessive gene.

• Hence carriers deviate Mendel's law of dominance, which possesses a recessive or non-expressive allele for a trait.

Therefore, option a. is the most accurate answer.    

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