NEET Question Frequency for GEN-02 Topics
| Topic | NEET Frequency | Question Type | Key Tested Concept |
|---|---|---|---|
| X-linked recessive inheritance crosses | Very High (yearly) | Punnett square, probability | Carrier female × normal male; offspring ratios |
| Chromosomal disorder karyotype identification | High (yearly) | Clinical features + karyotype | Down vs. Turner vs. Klinefelter |
| Sex determination systems | Medium-High | Identify system + heterogametic sex | ZW-ZZ (female heterogametic) |
| Sickle cell mutation | Medium-High | Molecular details | GAG→GUG; Glu→Val; chromosome 11 |
| Pedigree inheritance pattern | High (yearly) | Identify pattern from pedigree | Autosomal dominant vs. recessive vs. X-linked |
| Which parent determines sex | Medium | Conceptual | Father determines (XX-XY); mother determines (ZW-ZZ) |
PYQ-Specific Traps NEET Has Tested
- 2019: "47, XXY is a female" — WRONG. Answer: male (Klinefelter, Y = male).
- 2018: "Father cannot transmit X-linked haemophilia to son" — CORRECT. Answer: father gives Y to sons.
- 2017: "In birds, male is heterogametic" — WRONG. Answer: female is ZW heterogametic in birds.
- Multiple years: Probability of haemophilic child among ALL children (not just sons) from carrier mother × normal father = 1/4, not 1/2.
- Multiple years: Sickle cell — which amino acid is at position 6 in HbS? Answer: Valine (NOT glutamic acid, which is the NORMAL position 6 amino acid).
Exam Strategy
- Always first identify: autosome or sex chromosome disorder?
- For X-linked questions: trace X chromosomes, remember Y goes to sons always.
- For chromosomal disorders: always check if Y is present → male. No Y → female.
- Probability questions: calculate P(affected) per child first, then apply to specific family scenario.