IB DP Biology- A2.3 Viruses-IB Style Questions For HL Paper 1A -FA 2025

Question

Which statement describes a key difference between the lytic cycle and the lysogenic cycle of bacteriophage lambda?

A.  Only in the lytic cycle is lambda DNA inserted into the host DNA.
B.  Only in the lysogenic cycle is the host metabolism used to replicate.
C.  Only in the lytic cycle is the host metabolism used to replicate.
D.  Only in the lysogenic cycle is lambda DNA inserted into the host DNA.

▶️ Answer/Explanation

In the lysogenic cycle, lambda DNA becomes integrated into the host’s chromosome, remaining dormant until triggered. This insertion does not occur in the lytic cycle.
✅ Answer: (D)

Question

What is the name for the protein shell of a virus that encloses the genetic material?

(a) Virion

(b) Capsid

(d) Capsomers

▶️Answer/Explanation

Answer: (b)
Explanation:
The capsid is the protein shell that encloses the genetic material (DNA or RNA) of a virus.
It is made up of protein subunits called capsomers.

Question

What forms the genome of a virus?

(a) DNA

(b) RNA

(d) Both DNA and RNA

▶️Answer/Explanation

Answer: (c)

Explanation:

The genome of a virus can be made up of either DNA or RNA, but not both. It depends on the type of virus:

IB DP Biology- A2.3 Viruses-IB Style Questions For HL Paper 1A -FA 2025

Question

Question

Question

Resources

Members

Company