Question

Of the following statements, which is/are correct?
(A) During incomplete dominance, the modified allele is the dominant allele
(B) In polygenic inheritance, the effect of each allele is additive
(C) A gene is called pleiotropic when it exhibits multiple phenotypic expressions
(D) Mutation means alteration of DNA sequence which ensures change only in the phenotype of an organism
Choose the correct answer from the options given below:

• A. (A), (B), and (C) only
• B. (B) and (C) only
• C. (D) only
• D. (C) and (D) only

Answer 1

Answer: (B)

(B) and (C) only

Answer 2

Statement (B) is correct because, in polygenic inheritance, the effect of each allele is additive, meaning multiple alleles collectively influence the trait. Statement (C) is also correct; a gene is termed pleiotropic when it has multiple phenotypic effects. Statement (A) is incorrect because incomplete dominance involves a blending of traits, where neither allele is fully dominant. Statement (D) is incorrect since mutation can alter both genotype and phenotype, not necessarily affecting only the phenotype.