Q880
Match the following columns: Column I Column II a. Pure lines 1. Incomplete dominance b. Mirabilis jalapa 2. Johannsen c. Pleiotropy 3. Sickle-cell anaemia d. Co-dominance 4. Human blood groups
Match the following columns:
| Column I | Column II |
| a. Pure lines | 1. Incomplete dominance |
| b. Mirabilis jalapa | 2. Johannsen |
| c. Pleiotropy | 3. Sickle-cell anaemia |
| d. Co-dominance | 4. Human blood groups |
A.
a-1, b-2, c-3, d-4
B.
a-3, b-4, c-2, d-1
C.
a-2, b-1, c-3, d-4
AnswerD.
a-4, b-3, c-2, d-1
Answer: Option C
Solution
Answer: Option C
Solution:
a. Pure lines is the term proposed by Johannsen. A pure line means those breeds of organisms that have been generated through repeated self-fertilization and have become homozygous for a particular trait.b. Mirabilis Jalapa shows incomplete dominance because the genes for red and white colour mix in F1 to form pink hybrids. Both the pure characters reappear in the F2 generation.
c. Pleiotropy is observed in sickle cell anaemia. Changes in one gene can cause changes in two or more phenotypic features, a phenomenon known as pleiotropy.
d. Co-dominance in Human blood groups. Human blood type is determined by codominant alleles. The IA and IB alleles are codominant, and the i allele is recessive. The possible human phenotypes for the blood group are type A, type B, type AB and type O.