Question

A. influenza virus is unique because

1) it is difficult to transmit

2) it causes pandemic

3) it infect several different species of animal

4) it is an RNA virus replicating in the nucleus

B) which of the following is not part of nonspecific host defenses

1)macrophages

2) B lymphocytes

3) complement

4) phagocytosis

C) the incoming retroviral genome is used to make

1) provirus

2) viral protein

3) viral mRNA

4)viral genome

Answer 1

A. Answer : 4 ; It is an RNA virus replicating in the nucleus.

Explanation : Influenza virus or flu virus are made up with single stranded RNA nucleic acid, which enclosed in a nucleocapsid. On the outside of these viruses have an envelope, which is made up of hemagglutinin and neurominidase protein. This protein important to bind with host cell.

B. Answer : 3 ; Complement.

Explanation : in the given another options these are all a part of non-specific host difence, as we know that macrophage, B lymphocytes, is the first or front line cell of non specific host difence, and phagocytosis is a process in which if any harmful agent or virus or another harmful agent if enters in cell then the cell of lymphocytes undergoes phagocytosis to kill that virus or harmful agent.

C. Answer : 3 ; Viral mRNA.

Explanation : In that case retroviral genome it use to reverse transcription and make RNA genome to DNA. And here mRNA is that elongated with host genome and then it from a new DNA can form by the reverse transcription process,