Question

Match List- I with List- II
List-I (Genetic Term)
(A) Co-dominance
(B) Pleiotropy
(C) Epistasis
(D) Multiple allelism

List-II (Example)
(I) Flower colour in sweet pea
(II) Flower colour in snapdragon
(III) Fur coat in rabbit
(IV) Sickle cell anemia

Choose the correct answer from the options given below:

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

Hint:

Remember classic examples:
Co-dominance: ABO blood group, snapdragon (sometimes);
Pleiotropy: Sickle cell anemia, Marfan syndrome;
Epistasis: Sweet pea flower colour;
Multiple allelism: ABO blood group, rabbit fur colour.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Genetics involves various inheritance patterns:
Co-dominance, pleiotropy, epistasis, and multiple allelism.
Each has a distinct phenotypic effect.

Step 2: Key Approach:
Match the genetic term with its classic example.

Step 3: Detailed Explanation:
(A) Co-dominance: Both alleles express fully in the heterozygote.
Example: Flower colour in snapdragon (II) where red (RR) and white (WW) give pink (RW) in incomplete dominance?
Actually, snapdragon is an example of incomplete dominance, not co-dominance.
Co-dominance example is ABO blood group, but among the options, flower colour in snapdragon is incomplete dominance.
However, the question uses it as an example for co-dominance? Let's check:
Actually, the classic example of co-dominance is ABO blood group.
But here, snapdragon is given.
Wait, the question lists: (II) Flower colour in snapdragon.
Typically, snapdragon is for incomplete dominance.
Maybe the examiner considers it as co-dominance.
Let's see the rest:
(B) Pleiotropy: Single gene affects multiple traits.
Example: Sickle cell anemia (IV) affects red blood cells, causing various symptoms.
(C) Epistasis: One gene masks the expression of another.
Example: Flower colour in sweet pea (I) (Lathyrus odoratus) - the classic Bateson and Punnett experiment.
(D) Multiple allelism: More than two alleles for a gene.
Example: Fur coat in rabbit (III) (C, c\textsuperscript{h}, c\textsuperscript{ch}, c).
Thus, the correct matching is:
(A) - (II), (B) - (IV), (C) - (I), (D) - (III).
This is option (B).
Despite snapdragon being incomplete dominance in standard texts, in this context, it is paired with co-dominance.