Question

1. Which of the following are possible strategies for treating viral infection

1. Blocking uncoating of the virus after entry
2. Blocking synthesis of viral nucleic acids
3. Blocking viral attachment to host cell receptors
4. Blocking insertion of viral DNA into the host cell chromosomes
5. All of the above

2. A double-stranded, enveloped RNA virus that contains reverse transcriptase belongs to which family?

1. Poxviridae
2. Hepadnaviridae
3. Retroviridae
4. Picornaviridae
5. Rhabdoviridae

3. E.coli makes insulin because _.

1. It picked up the insulin gene from another cell
2. It is an ancient gene that now has no function
3. It needs to regulate its cell-glucose level
4. The insulin gene was inserted into E.coli DNA
5. There is no reason. E.coli is unable to make insulin.

4. Which enzyme would cut this strand of DNA : GCATGGATCCCAATGC?

1. Enzyme – EcoRl
2. Enzyme – Hind III
3. Enzyme – Bam HI
4. Enzyme – Hale III
5. Enzyme – Pst I

Answer 1

1) The correct answer is-

E- all of the above

This is because the viral infection can be stopped if the uncoating of the virus is blocked due to which the virus will not be able to release its nucleic acid and thereby it would not be able to replicate in host cells. Blocking synthesis of viral nucleic acid and insertion of its nucleic acid to host cell chromosomes too can stop the replication of the virus in the host cells. After the virus enters, it attaches to a receptor in the host cell, blocking the attachment of the virus to the receptor would further prevent its replication.

2)The correct answer is-

C- retroviridae

Retroviridae also known as retrovirus are RNA viruses which uses reverse transciptase enzyme to convert its RNA to DNA intermediate and then incorporate into the host chromosome.

3) The correct answer is-

D- The insulin gene was inserted into E.coli DNA

This is because E coli cannot produce insulin on its own. It produces insulin only when the insulin gene is inserted into the E coli gene.

4) The correct answer is -

C- BamHI

This is because-

EcoRI site is - GAATTC (between G and A) - not present

HindIII site is- AAGCTT (between A and A) - not present

BamHI site is- GGATCC (between G and G) - present

HaeIII site is - GGCC

PstI site is - CTGCAG (between A and G) - not present

After BamHI digestion-

GCATG GATCCCAATGC