UHS Punjab MDCAT Biology Inheritance Set 2

UHS Punjab MDCAT Biology Inheritance — Set 2

Question 1
Q1. What is the term for the phenomenon where a dominant allele has a reduced effect due to the presence of a recessive allele?
- A) Incomplete dominance
- B) Codominance
- C) Dominance
- D) Epistasis
Answer: Incomplete dominance
Explanation: Incomplete dominance results in a blending of traits, reduced effect of dominant allele
Question 2
Q2. In a family with a history of an X-linked recessive disorder, what is the probability that a female carrier will pass the disorder to her sons?
- A) 25%
- B) 50%
- C) 100%
- D) 0%
Answer: 50%
Explanation: X-linked recessive disorders, 50% chance of female carrier passing to sons
Question 3
Q3. What is the term for the interaction between two or more genes that affect a single trait?
- A) Epistasis
- B) Polygenic inheritance
- C) Pleiotropy
- D) Genetic drift
Answer: Epistasis
Explanation: Epistasis refers to gene interaction, polygenic inheritance refers to multiple genes affecting a trait
Question 4
Q4. A plant with red flowers is crossed with a plant with white flowers. The offspring have pink flowers. What type of inheritance is this an example of?
- A) Incomplete dominance
- B) Codominance
- C) Dominance
- D) Epistasis
Answer: Incomplete dominance
Explanation: Incomplete dominance results in a blending of traits, pink flowers
Question 5
Q5. What is the term for the phenomenon where a single gene affects multiple traits?
- A) Pleiotropy
- B) Epistasis
- C) Polygenic inheritance
- D) Genetic drift
Answer: Pleiotropy
Explanation: Pleiotropy refers to a single gene affecting multiple traits
Question 6
Q6. In a population, the frequency of a recessive allele is 0.2. What is the frequency of the dominant allele?
- A) 0.8
- B) 0.4
- C) 0.6
- D) 0.1
Answer: 0.8
Explanation: Frequency of dominant allele is 1 - frequency of recessive allele, 1 - 0.2 = 0.8
Question 7
Q7. A couple has a child with an autosomal dominant disorder. What is the probability that their next child will have the disorder?
- A) 25%
- B) 50%
- C) 100%
- D) 0%
Answer: 50%
Explanation: Autosomal dominant disorder, 50% chance of offspring inheriting the disorder
Question 8
Q8. What is the term for the random change in the frequency of a gene or trait in a population over time?
- A) Genetic drift
- B) Natural selection
- C) Mutation
- D) Gene flow
Answer: Genetic drift
Explanation: Genetic drift refers to random change in gene frequency
Question 9
Q9. In a population, the frequency of a dominant allele is 0.8. What is the frequency of the recessive allele?
- A) 0.2
- B) 0.4
- C) 0.6
- D) 0.1
Answer: 0.2
Explanation: Frequency of recessive allele is 1 - frequency of dominant allele, 1 - 0.8 = 0.2
Question 10
Q10. A plant with tall stems is crossed with a plant with short stems. The offspring have tall stems. What type of inheritance is this an example of?
- A) Dominance
- B) Incomplete dominance
- C) Codominance
- D) Epistasis
Answer: Dominance
Explanation: Dominance results in one allele having a greater effect than the other, tall stems
Question 11
Q11. What is the term for the movement of genes from one population to another?
- A) Gene flow
- B) Genetic drift
- C) Mutation
- D) Natural selection
Answer: Gene flow
Explanation: Gene flow refers to the movement of genes between populations
Question 12
Q12. In a family with a history of a mitochondrial disorder, what is the probability that a mother will pass the disorder to her children?
- A) 25%
- B) 50%
- C) 100%
- D) 0%
Answer: 100%
Explanation: Mitochondrial disorders are inherited solely from the mother, 100% chance of passing to children
Question 13
Q13. What is the term for the phenomenon where a single gene has multiple effects on an organism?
- A) Pleiotropy
- B) Epistasis
- C) Polygenic inheritance
- D) Genetic drift
Answer: Pleiotropy
Explanation: Pleiotropy refers to a single gene having multiple effects
Question 14
Q14. In a population, the frequency of a recessive allele is 0.4. What is the frequency of the dominant allele?
- A) 0.6
- B) 0.8
- C) 0.2
- D) 0.1
Answer: 0.6
Explanation: Frequency of dominant allele is 1 - frequency of recessive allele, 1 - 0.4 = 0.6
Question 15
Q15. A couple has a child with an autosomal recessive disorder. What is the probability that their next child will be a carrier?
- A) 25%
- B) 50%
- C) 66%
- D) 33%
Answer: 50%
Explanation: Autosomal recessive disorder, 50% chance of offspring being a carrier
Question 16
Q16. What is the term for the process by which a population becomes reproductively isolated from other populations?
- A) Speciation
- B) Genetic drift
- C) Mutation
- D) Gene flow
Answer: Speciation
Explanation: Speciation refers to the formation of a new species, reproductive isolation
Question 17
Q17. In a dihybrid cross, what occurs when two different alleles of a gene are paired?
- A) Incomplete dominance
- B) Codominance
- C) Autosomal recessive inheritance
- D) Genotypic ratio
Answer: Codominance
Explanation: Codominance: both alleles have effect, unlike incomplete dominance.
Question 18
Q18. What type of genetic drift occurs when a new population is formed from a small group of individuals?
- A) Bottleneck effect
- B) Founder effect
- C) Gene flow
- D) Natural selection
Answer: Founder effect
Explanation: Founder effect: small group of individuals founds new population, reducing genetic variation.
Question 19
Q19. Which of the following is an example of a polygenic trait?
- A) Cystic fibrosis
- B) Sickle cell anemia
- C) Height
- D) Muscular dystrophy
Answer: Height
Explanation: Height: influenced by multiple genes, not a single gene.
Question 20
Q20. What is the term for the physical appearance of a trait?
- A) Genotype
- B) Phenotype
- C) Dominant allele
- D) Recessive allele
Answer: Phenotype
Explanation: Phenotype: physical appearance, unlike genotype which is genetic makeup.