Ziauddin University Medical Entry Test Biology Inheritance — Set 3

Ziauddin University Medical Entry Test Biology Inheritance — Set 3

1. Question 1

   Q1. What is the process by which an individual's genotype is determined by its parents' genotypes?

   • A) Mutation
   • B) Genetic drift
   • C) Gene flow
   • D) Mendelian inheritance

   Answer: Mendelian inheritance

   Explanation: Mendelian inheritance: genotype determined by parents' genotypes, not random events.

2. Question 2

   Q2. What is the term for the movement of individuals with a particular genotype into a new population?

   • A) Gene flow
   • B) Genetic drift
   • C) Mutation
   • D) Natural selection

   Answer: Gene flow

   Explanation: Gene flow: movement of individuals with a particular genotype, not genetic drift.

3. Question 3

   Q3. A plant has the genotype 'Rr' for the trait of red flowers. What is the probability that it will produce offspring with red flowers?

   • A) 25%
   • B) 50%
   • C) 75%
   • D) 100%

   Answer: 50%

   Explanation: 50%: 'Rr' plant has 50% chance of passing on 'R' allele.

4. Question 4

   Q4. What is the term for the change in the frequency of a particular allele in a population over time?

   • A) Genetic drift
   • B) Gene flow
   • C) Mutation
   • D) Natural selection

   Answer: Genetic drift

   Explanation: Genetic drift: change in allele frequency, not gene flow or mutation.

5. Question 5

   Q5. In a population, what is the term for the proportion of individuals with a particular genotype?

   • A) Allele frequency
   • B) Genotype frequency
   • C) Phenotype frequency
   • D) Gene frequency

   Answer: Genotype frequency

   Explanation: Genotype frequency: proportion of individuals with a particular genotype.

6. Question 6

   Q6. A couple has a child with an X-linked recessive disorder. What is the probability that their next child will also have the disorder?

   • A) 25%
   • B) 50%
   • C) 75%
   • D) 100%

   Answer: 25%

   Explanation: 25%: each son has 25% chance of inheriting X-linked recessive allele.

7. Question 7

   Q7. In a population, what is the term for the total number of genes for a particular trait?

   • A) Gene pool
   • B) Genotype
   • C) Phenotype
   • D) Genome

   Answer: Gene pool

   Explanation: Gene pool: total number of genes, not genotype or phenotype.

8. Question 8

   Q8. A couple has a child with a dominant disorder. What is the probability that their next child will also have the disorder?

   • A) 25%
   • B) 50%
   • C) 75%
   • D) 100%

   Answer: 50%

   Explanation: 50%: each child has 50% chance of inheriting dominant allele.

9. Question 9

   Q9. What is the term for the process by which a population becomes more adapted to its environment?

   • A) Natural selection
   • B) Genetic drift
   • C) Gene flow
   • D) Mutation

   Answer: Natural selection

   Explanation: Natural selection: process by which population becomes more adapted.

10. Question 10

    Q10. In a dihybrid cross, what is the probability of producing offspring with the genotype 'AaBb'?

    • A) 9/16
    • B) 3/16
    • C) 1/4
    • D) 1/16

    Answer: 3/16

    Explanation: 3/16: probability of producing offspring with genotype 'AaBb'.

11. Question 11

    Q11. In a dihybrid cross, what is the expected phenotypic ratio of offspring if two genes are inherited together?

    • A) 9:3:3:1
    • B) 1:1
    • C) 3:1
    • D) 2:1

    Answer: 9:3:3:1

    Explanation: Dihybrid cross follows 9:3:3:1 ratio, option B is incorrect because it represents a monohybrid cross.

12. Question 12

    Q12. A couple has a child with cystic fibrosis, an autosomal recessive disorder. What is the probability that their next child will also have cystic fibrosis?

    • A) 25%
    • B) 50%
    • C) 75%
    • D) 100%

    Answer: 25%

    Explanation: Autosomal recessive disorders have a 25% chance of being passed to offspring, option B is incorrect because it represents the chance of being a carrier.

13. Question 13

    Q13. What is the process by which genetic information is passed from one generation to the next?

    • A) Mutation
    • B) Genetic drift
    • C) Gene flow
    • D) Hereditary

    Answer: Hereditary

    Explanation: Hereditary refers to the passing of traits, option A is incorrect because it refers to a change in genetic information.

14. Question 14

    Q14. In a pedigree chart, what does a filled-in symbol represent?

    • A) Carrier of a disease
    • B) Affected individual
    • C) Unaffected individual
    • D) Deceased individual

    Answer: Affected individual

    Explanation: Filled-in symbols represent affected individuals, option A is incorrect because it represents a carrier, not an affected individual.

15. Question 15

    Q15. What is the term for a gene that has multiple effects on an organism's phenotype?

    • A) Pleiotropy
    • B) Polygenic
    • C) Incomplete dominance
    • D) Codominance

    Answer: Pleiotropy

    Explanation: Pleiotropy refers to multiple effects, option B is incorrect because it refers to multiple genes influencing a single trait.

16. Question 16

    Q16. A genetic disorder is caused by a mutation in a gene that codes for a protein involved in muscle contraction. What type of inheritance pattern would this disorder likely follow?

    • A) Autosomal dominant
    • B) Autosomal recessive
    • C) X-linked dominant
    • D) X-linked recessive

    Answer: Autosomal recessive

    Explanation: Autosomal recessive disorders are often caused by mutations in genes coding for proteins, option A is incorrect because dominant disorders are often caused by gain-of-function mutations.

17. Question 17

    Q17. What is the term for the interaction between two or more genes to produce a single phenotype?

    • A) Epistasis
    • B) Pleiotropy
    • C) Polygenic
    • D) Genetic drift

    Answer: Epistasis

    Explanation: Epistasis refers to gene interaction, option B is incorrect because it refers to multiple effects of a single gene.

18. Question 18

    Q18. In a test cross, what is the purpose of crossing an individual with a homozygous recessive individual?

    • A) To determine the genotype of the individual
    • B) To determine the phenotype of the individual
    • C) To introduce new genetic variation
    • D) To increase the fitness of the individual

    Answer: To determine the genotype of the individual

    Explanation: Test cross determines genotype, option B is incorrect because phenotype is already known.

19. Question 19

    Q19. What is the term for a gene that is located on the X chromosome?

    • A) Autosomal
    • B) X-linked
    • C) Y-linked
    • D) Mitochondrial

    Answer: X-linked

    Explanation: X-linked genes are located on the X chromosome, option A is incorrect because autosomal genes are located on non-sex chromosomes.

20. Question 20

    Q20. What is the term for the phenomenon where two or more genes interact to produce a single phenotype?

    • A) Epistasis
    • B) Pleiotropy
    • C) Polygenic
    • D) Genetic drift

    Answer: Epistasis

    Explanation: Epistasis refers to gene interaction, option B is incorrect because pleiotropy refers to multiple effects of a single gene.