Question

Match List-I with List-II:

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (II), (B) - (III), (C) - (IV), (D) - (I)
• (A) - (II), (B) - (IV), (C) - (III), (D) - (I)

Hint:

Co-dominance: Both alleles show; Pleiotropy: One gene, many traits; Epistasis: Gene masking; Multiple allelism: Many alleles for one gene.

Answer 1

The Correct Option is B

The correct matching of genetic concepts with their examples is as follows:
- (A) Co-dominance (II - Flower colour in snapdragon): In co-dominance, both alleles are fully expressed in the heterozygote. In snapdragons, a cross between red (RR) and white (WW) flowers produces pink (RW) flowers, where both alleles contribute to the phenotype (incomplete dominance is often confused here, but snapdragons are a classic co-dominance example in some contexts).
- (B) Pleiotropy (IV - Sickle cell anemia): Pleiotropy occurs when a single gene affects multiple traits. In sickle cell anemia, the mutated hemoglobin gene causes red blood cell sickling, anemia, and other systemic effects, impacting multiple body systems.
- (C) Epistasis (I - Flower colour in sweet pea): Epistasis occurs when one gene masks or modifies the effect of another. In sweet peas, flower color (e.g., purple vs. white) is controlled by two genes, where one gene’s expression is necessary for the other to produce color, demonstrating epistatic interaction.
- (D) Multiple allelism (III - Fur coat in rabbit): Multiple allelism refers to the existence of more than two alleles for a gene. In rabbits, the coat color gene has multiple alleles (e.g., C, cch, ch, c) controlling full color, chinchilla, Himalayan, and albino phenotypes.
Thus, the correct pairing is (A) - (II), (B) - (IV), (C) - (I), (D) - (III), making option (2) correct.

Answer 2

Concept-signature matching:
Each genetics term has a recognizable signature: co-dominance shows both parental phenotypes together, not a blended one, as in the AB blood group. Pleiotropy is recognized when a single mutant gene produces many unrelated symptoms across body systems, the hallmark of sickle-cell disease. Epistasis is recognized when one gene switches another gene's expression on or off, as with the pigment-producing gene in sweet pea flower colour, and multiple allelism is recognized whenever more than two alleles exist at one locus, the C-series coat-colour alleles in rabbits. Matching these signatures gives (A) Co-dominance-II, (B) Pleiotropy-IV, (C) Epistasis-I, (D) Multiple allelism-III, option (2).