Question

1. Viruses are not considered alive, but instead are thought of as ___________________ chemicals.

2. Viruses lack several abilities cellular life forms have, such as:

__________________________________________________________

3. Phages are ________________________________

4. Viral genomes may be composed of _____________ or _______________

5. Viruses have a protein coat called a ______________________

6. Some viruses are surrounded by a second outer layer called _______________

composed of _______________________________________________

7. What is the difference between the lytic cycle and the lysogenic cycle?

         _____________________________________________________________

_____________________________________________________________

8. The HIV virus binds to ______________________ cells in the human body

9. What are prions? _______________________________________________

10. Why don’t hand sanitizers inactivate cold viruses? ____________________

Answer 1

• Viruses are not considered alive, but instead are thought of as biological chemicals.
• Viruses lack several abilities cellular life forms have, such as : It does not have its own metabolic activity, they dont have acytoplasm or cell organelles, and they also do not show growth i,e they dont chage their size or chemical composition
• Phages are viruses that infects and replicates within a bacteria
• Viral genomes may be composed of RNA or DNA
• Viruses have a protein coat called a capsid
• Some viruses are surrounded by a second outer layer called viral envelope composed of lipoprotiens
• What is the difference between the lytic cycle and the lysogenic cycle?   

Lytic cycle	Lysogenic cycle
Viral DNA destroys the cell DNA, takes control over cellular functions	No such cell destruction takes place
Virus produces progenies	No replication and production of progenies
shows symptoms of viral infection	No such symptoms are shown

• The HIV virus binds to T- helper cells in the human body
• What are prions? They are basically protienaceous infectious particles responsible for several fatal and transittable diseases like Creutzfeldt - Jakob disease
• Why don’t hand sanitizers inactivate cold viruses? The mucous coat of the virus acts as a hydrogel and protects the virus from ethanol. The time for which alcohol is in contact with virus is less than the time which is required to inactivate the virus . Hence the sanitizer becomes ineffective