FSc Pre-Medical Biology: Inheritance MCQs

FSc Pre-Medical Biology: Inheritance MCQs — sample questions

1. Question 1

   Q1. If a couple has a child with cystic fibrosis, an autosomal recessive disorder, what is the probability that their next child will be a carrier?

   • A) 1/2
   • B) 1/3
   • C) 2/3
   • D) 3/4

   Answer: 2/3

   Explanation: Both parents must be carriers, so 2/3 chance the next child is a carrier.

2. Question 2

   Q2. What is the purpose of the leading strand during DNA replication?

   • A) To synthesize the lagging strand
   • B) To synthesize the leading strand
   • C) To unwind the double helix
   • D) To proofread the new DNA

   Answer: To synthesize the leading strand

   Explanation: Leading strand is synthesized continuously in the 5' to 3' direction.

3. Question 3

   Q3. A couple has a child with a genetic disorder caused by a dominant allele. What is the probability that the next child will have the disorder?

   • A) 1/2
   • B) 1/3
   • C) 1/4
   • D) 2/3

   Answer: 1/2

   Explanation: Each child has a 50% chance of inheriting the dominant allele.

4. Question 4

   Q4. A genetic test reveals that a couple's child has a chromosomal abnormality. What is the term for the presence of an extra copy of a chromosome?

   • A) Aneuploidy
   • B) Polyploidy
   • C) Triploidy
   • D) Trisomy

   Answer: Trisomy

   Explanation: Trisomy refers to the presence of an extra chromosome, such as in Down syndrome.

5. Question 5

   Q5. What is the term for the movement of molecules from an area of higher concentration to an area of lower concentration?

   • A) Osmosis
   • B) Diffusion
   • C) Active transport
   • D) Passive transport

   Answer: Diffusion

   Explanation: Diffusion is the movement of molecules down a concentration gradient.