Mendel's Laws of Inheritance — NEET Biology

Correct answer: A — A-3-II, B-1-I, C-2-III

This question requires linking Mendel's laws with their underlying principles, cytological bases, and expected F2 ratios. - A. Law of Dominance: This law states that in a dissimilar pair of factors, one member dominates the other. This explains the expression of only one trait in a heterozygous individual (Column II - 3) and results in the 3:1 phenotypic ratio in the F2 generation of a monohybrid cross (Column III - II). - B. Law of Segregation: This law is based on the fact that alleles of a pair segregate from each other during gamete formation, so each gamete receives only one allele. The cytological basis for this is the segregation of homologous chromosomes during meiosis I (Column II - 1). This leads to a 1:2:1 genotypic ratio in the F2 generation of a monohybrid cross (Column III - I). - C. Law of Independent Assortment: This law states that when two pairs of traits are combined in a hybrid, segregation of one pair is independent of the other. The cytological basis is the independent alignment of non-homologous chromosome pairs at metaphase I (Column II - 2). This results in the characteristic 9:3:3:1 phenotypic ratio in the F2 generation of a dihybrid cross (Column III - III). Therefore, the correct match is A-3-II, B-1-I, C-2-III.