MDCAT Biology — Inheritance
Inheritance is a core Biology topic in the PMDC MDCAT syllabus, covering 14 subtopics. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (14)
- Chromosomal Disorders
- Gene Interaction (Epistasis)
- Gene Linkage and Crossing Over
- Gene Location and Mapping
- Gene Mutation
- Genetics
- Human Disorders
- Incomplete Dominance and Codominance
- Mendel's Laws of Inheritance
- Mendelian
- Polygenic inheritance
- Sex Determination
- Sex-linked
- X-linked Recessive Inheritance
How Inheritance is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Inheritance accounts for 92 questions. It appears in all 16, about 5.8 questions a paper. The heaviest was MDCAT 2017, with 8 questions, and the most recent is MDCAT 2025, with 7.
| Paper | Questions |
|---|---|
| MDCAT 2025 | 7 |
| MDCAT 2024 | 2 |
| MDCAT 2023 | 6 |
| MDCAT 2022 | 4 |
| MDCAT 2019 | 6 |
| MDCAT 2018 | 6 |
| MDCAT 2017 | 8 |
| MDCAT 2016 | 7 |
| MDCAT 2015 | 8 |
| MDCAT 2014 | 4 |
| MDCAT 2013 | 4 |
| MDCAT 2012 | 7 |
| MDCAT 2011 | 7 |
| MDCAT 2010 | 6 |
| MDCAT 2009 | 5 |
| MDCAT 2008 | 5 |
Inheritance MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2025 · Inheritance
The 9:3:3:1 ratio of law of independent assortment can be affected by
- A.Genetic drift
- B.Small population
- C.Gene linkage
- D.Gene duplication
Show answer
Answer: C. Gene linkage — Gene linkage disrupts the 9:3:3:1 dihybrid ratio.
- Q2 · MDCAT 2024 · Inheritance
The formula calculating the frequency of genotypes and alleles in a population gene pool is known as:
- A.Hardy-Weinberg Equation
- B.Lamarck Equation
- C.Darwin Equation
- D.James Hutton Equation
Show answer
Answer: A. Hardy-Weinberg Equation — The Hardy-Weinberg equation calculates allele/genotype frequencies in a population's gene pool.
- Q3 · MDCAT 2023 · Inheritance
ABO blood group is controlled by more than two alleles in a population. This shows that ABO blood group is an example of:
- A.Polygenic Inheritance
- B.Multiple Alleles
- C.Operons
- D.Allelic interaction
Show answer
Answer: B. Multiple Alleles — The ABO blood group system, controlled by three alleles (IA, IB, i) in the population, is a classic example of multiple alleles.