BLS108: Virology UE 2014
Question 1:
(a) Briefly, hypothesize the origin of viruses (6 marks)
(b) Provide THREE (3) functions for each of the following viral components
(i) Viral proteins (3 marks)
(ii) Viral capsid (3 marks)
(iii) Viral envelope (3 marks)
(c) Using a diagram alone, illustrate the Baltimore classification system (5 marks)
Question 2:
(a) Viruses hijack cellular processes in living cells in order to complete their replication cycle. With examples,
i. briefly explain ONE stage that can occur in dead cells (5 marks)
ii. briefly explain ONE stage that cannot occur in dead cells (5 marks)
(b) To complete their replication cycle, viruses utilize several enzymes.
i. with examples, briefly explain why viruses package enzymes within their virions (5 marks)
ii. with examples, briefly explain why viruses package enzymes within their envelope (5 marks)
Question 3:
(a) Dengue virus is a single-stranded positive sense RNA virus.
i. mention the common features between the dengue virus genome and cellular nucleic acids (5 marks)
ii. briefly describe how the dengue genome is replicated (5 marks)
(b) Virions are composed up of structural and non-structural proteins. With examples, write short notes on
i. the functions of viral structural proteins (5 marks)
ii. the functions of viral non-structural proteins (5 marks)
Question 4:
Write short notes on the mechanism of action of the following antiviral agents:
(a) zidovudine/AZT (5 marks)
(b) enfuvirtide (T-20) (5 marks)
(c) amantadine (5 marks)
(d) oseltamivir (5 marks)
Question 5:
Write short notes on the following:
(a) Role of movement proteins in virus infection in plants (10 marks)
(b) Mechanism(s) of imparting resistance against virus infection in plants (10 marks)