Principles of Inheritance and Variation: NEET questions with solutions

Principles of Inheritance and Variation builds from Mendel's monohybrid and dihybrid crosses to deviations such as incomplete dominance, co-dominance and multiple alleles, then to the chromosomal theory, linkage, sex determination, and Mendelian and chromosomal disorders. NEET frequently sets numerical cross problems (ratios, probabilities) and pedigree-based questions on X-linked recessive disorders. Marks are often lost through arithmetic slips in ratio calculations and mixing up the karyotypes of Down, Klinefelter and Turner syndromes.

1. 1.Mendel crossed a true-breeding tall pea plant (TT) with a true-breeding dwarf pea plant (tt). All F₁ plants were tall, but when the F₁…Mendel's Laws of InheritanceEasySingle correct
2. 2.A pea plant with the genotype Tt is grown and its outward height (tall) is recorded. With respect to the height gene, this plant is best…Mendel's Laws of InheritanceEasySingle correct
3. 3.In garden pea, round seed shape (R) is dominant over wrinkled (r), and yellow seed colour (Y) is dominant over green (y); the two genes…Inheritance of Two GenesMediumSingle correct
4. 4.In the dog flower (snapdragon, Antirrhinum sp.), flower colour shows incomplete dominance: a true-breeding red-flowered plant (RR) crossed…Deviations from Mendelism — Incomplete DominanceMediumSingle correct
5. 5.The ABO blood group in humans is controlled by multiple alleles IA, IB and i, where IA and IB are co-dominant and both are dominant over i.…Deviations from Mendelism — Multiple AllelesMediumSingle correct
6. 6.With respect to linkage and recombination, which statement(s) is/are correct?Chromosomal Theory of Inheritance — Linkage and RecombinationMediumStatement based
7. 7.Regarding sex-determination mechanisms, which statement(s) is/are correct?Sex DeterminationMediumStatement based
8. 8.Haemophilia is a sex-linked disorder in which a single protein of the blood-clotting cascade is affected, so even a small cut can bleed…Pedigree Analysis and Mendelian DisordersHardAssertion–Reason
9. 9.Sickle-cell anaemia is caused by the substitution of a single amino acid in the beta-globin chain of haemoglobin, which makes red blood…Mendelian Disorders — Sickle-cell AnaemiaEasySingle correct
10. 10.Match the condition in Column I with its correct karyotype/chromosomal basis in Column II, then choose the option in which all four matches…Chromosomal DisordersHardMatch the following