Take this Exam: A-Level Biology: The Immune System | Zestly

Question 1

Why are antibiotics ineffective against HIV?

Accepted Answer

Because antibiotics target bacterial metabolic pathways not present in viruses.

Question 2

In an ELISA test, what is the purpose of the enzyme-linked antibody?

Accepted Answer

To produce a color change when a substrate is added, indicating the presence of the target antigen.

Question 3

What is the primary challenge posed by antigen variability in pathogens like HIV or influenza?

Accepted Answer

Memory cells from previous infections may not recognize the new antigen variants.

Question 4

Which of the following statements regarding herd immunity are correct?

Answer

It reduces the probability of an susceptible individual encountering an infected person.

Answer

It relies on every single member of the population being vaccinated.

Answer

It provides permanent protection to all individuals regardless of vaccination status.

Answer

It is achieved when a sufficient percentage of the population is immune.

Question 5

What is the role of the reverse transcriptase enzyme in the replication cycle of HIV?

Answer

To integrate viral DNA into the host genome.

Answer

To translate viral mRNA into viral proteins.

Answer

To synthesize viral DNA from the viral RNA genome.

Answer

To break down the host cell membrane for viral release.