Match List I with List II

Choose the correct answer from the options given below:

A-I, B-IV, C-II, D-III

The correct answer is Option (1) → A-I, B-IV, C-II, D-III

A. Mendel’s Law of Independent Assortment: The law states that ‘when two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters’. This law is illustrated by a 9:3:3:1 phenotypic ratio, which is observed in a dihybrid cross (a cross involving two different traits). For example, when crossing plants with different seed shapes and colors, this ratio indicates the different combinations of these traits in the offspring.

B. The inheritance of flower colour in the dog flower (snapdragon or Antirrhinum sp.) is a good example to understand incomplete dominance. In a cross between true-breeding red-flowered (RR) and true- breeding white-flowered plants (rr), the F1 (Rr) was pink.

C. The law of dominance is used to explain the expression of only one of the parental characters in a monohybrid cross in the F₁ and the expression of both in the F₂. It also explains the proportion of 3:1 obtained at the F₂.

D. Co-dominance occurs when both alleles in a heterozygous individual contribute to the phenotype. In the case of the ABO blood group system, the I^A and I^B alleles are co-dominant. This means that if an individual has both I^A and I^B alleles (genotype I^AI^B), both alleles are expressed, and the individual has blood type AB, which has both A and B antigens on the surface of the red blood cells. A good example of co-dominance is different types of red blood cells that determine ABO blood grouping in human beings.