NEET · Class 12 Biology
Principles of Inheritance and Variation MCQs for NEET
Genetics carries a big share of NEET Biology marks and rewards practice more than reading. Work through these questions, then take a full test in the app to see which parts of the chapter you are weak in.
Take the free 10-question testFree PDF revision sheet — Principles of Inheritance and Variation
One printable page-set with the NCERT recap, exam tips and all 4 questions with answers and reasons. Free to share and print.
Practice questions on Principles of Inheritance and Variation
Q1. A cross between two pink flowered Mirabilis jalapa plants gives what phenotypic ratio?
Q2. ABO blood grouping in humans is an example of:
Q3. A colour blind man marries a woman with no carrier gene. Their children will be:
Q4. Down's syndrome is caused by:
Quick NCERT recap
- Mendel's laws: dominance, segregation (law of purity of gametes) and independent assortment.
- Monohybrid ratio 3:1 phenotypic, 1:2:1 genotypic; dihybrid ratio 9:3:3:1.
- Incomplete dominance (Mirabilis, 1:2:1) and co-dominance (ABO blood group) are exceptions to dominance.
- Linked genes do not assort independently; recombination frequency measures the map distance between them.
- Haemophilia and colour blindness are X-linked recessive; sickle cell anaemia and thalassaemia are autosomal recessive.
Exam tips for this chapter
- Practise pedigree questions — one comes almost every year.
- Learn the difference between Down's syndrome (trisomy 21), Klinefelter's (XXY) and Turner's (XO) by chromosome number.
- For dihybrid crosses, use the forked-line method instead of drawing a full 16-box Punnett square in the exam.
Common questions
Is NCERT enough for NEET genetics?
NCERT covers the theory, but you need repeated question practice for crosses and pedigrees. That is exactly what the daily 10-question test in the app is for.
Which part of genetics is asked the most?
Mendelian ratios, pedigree analysis, sex-linked inheritance and chromosomal disorders appear most often in NEET.