BIOLOGIC
INSIGHTS
⚡ NEET 2025 GENETICS DECODER
PRINCIPLES OF INHERITANCE
20-Year NEET Analysis | 100% NCERT + 5 Topper Secrets
💎 3 GOLDEN FACTS (NEET 2004-24)
18
PYQs on Dihybrid Cross
95%
Blood Group Qs from NCERT
7x
Pedigree Analysis Questions
🧬 DOMINANCE vs CODOMINANCE: NEET's Favourite Comparison
| Feature | Complete Dominance | Codominance | NEET Frequency |
|---|---|---|---|
| Phenotype Ratio | 3:1 (F₂) | 1:2:1 (F₂) | 6 Qs (2020-24) |
| Example | Mendel's Pea Plants | AB Blood Group | 4 Qs (2019-23) |
| Expression | Dominant masks Recessive | Both alleles expressed | 5 Qs (2018-22) |
🧬 Mendel's Laws Decoded
Law of Segregation → Alleles separate during gamete formation
NEET Hotspot: "Test cross ratio 1:1 = Heterozygous parent"
🎯 5-Year Trend: 2 marks/year on dihybrid cross (9:3:3:1)
📊 Pedigree Analysis Hacks
Quick Rules:
- Affected child + Normal parents = Recessive
- Every generation affected = Dominant
- More males affected = X-linked
NEET Mnemonic:
"DAD" - Dominant Affects Dad (male-to-male transmission possible)
🧬 Chromosomal Disorders - NEET's Favorite
Trisomy 21:
- 47 chromosomes
- Flat face, slanted eyes
- NEET 2022, 2020
Klinefelter (XXY):
- Male with gynecomastia
- Sterile
- NEET 2021, 2019
Pro Tip: "Turner = XO (45), Klinefelter = XXY (47)" - NEET 2023 question
📜 10-Year PYQ Goldmine
2023: Test cross ratio for heterozygous parent?
1:1
2021: AB blood group shows which inheritance?
Codominance
2019: Karyotype of Turner syndrome?
45, XO
🚨 NEET ALERT!
Pedigree Analysis asked 5 years consecutively - Master it now!
