BLS 2022

 SOKOINE UNIVERSITY OF AGRICULTURE

COLLEGE OF VETERINARY AND MEDICAL SCIENCES

UNIVERSITY EXAMINATION FOR 1^st YEAR BACHELOR OF BIOTECHNOLOGY AND LABORATORY SCIENCES

Course Ante:   BLS 113  Course Title:  Virology

 DATE:  14^th July 2022

 TIME: 3:30-6:30 pm

 INSTRUCTIONS: ATTEMPT ALL QUESTIONS

                          Use nicely labeled diagrams the place mandatory

VENUE:                                                        

                             

QUESTION ONE (25 Marks)

a) Record FOUR sorts of subviral brokers and state why EACH of those subviral brokers doesn’t adjust to the classical definition of a “virus.” (8 marks)

b) Record TWO traits that viruses share with dwelling organisms and clarify why viruses don’t match our standard definition of life (7 marks)

c) Briefly describe how every of the seven teams of viruses (based mostly on Baltimore classification) match into the central dogma of life (10 marks)

 

QUESTION TWO (25 Marks)

a) Describe 4 shapes of viruses based mostly on their symmetry (8 marks)

b) State why bacteriophages are extra advanced than typical icosahedral or helical viruses (5 marks)

c) What are the features of the capsid? (6 marks)

d) Identify and describe THREE viral properties which might be used to categorise viruses? (6 marks)

 

QUESTION THREE (25 Marks)

The determine under represents a replication cycle of an enveloped adverse sense single-stranded RNA virus. Use it to reply the questions under it.

a) The virus within the determine above begins its replication cycle by attaching to a receptor on the plasma membrane of host cell. Why would a cell possess a receptor that the virus may adsorb to? (4 marks)

b) Identify the processes happening at A, B, C, D, E and F (6 marks)

c) Briefly describe how the viral genome, mRNA and proteins are synthesized by the virus represented within the determine above? (9 marks)

d) How does the virus within the determine above acquire its envelope? (6 marks)

 

QUESTION FOUR (25 Marks)

a) Identify any FIVE routes of viral entry into the physique and any THREE routes for virus shedding (8 marks)

b) Can viruses replicate within the pores and skin? Why or why not? (2 marks)

c) Describe any FOUR methods viruses can injury contaminated host cells (12 marks)

d) What are the THREE generally proposed mechanisms for the origins of viruses? (3 marks)

                                                                              

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