1. What is a virus primarily composed of?
a. Nucleic acid and protein coat
b. Lipids and carbohydrates
c. Enzymes and organelles
d. Cell membrane and cytoplasm
Answer: a. Nucleic acid and protein coat
2. Which type of nucleic acid can be found in a virus?
a. DNA only
b. RNA only
c. Both DNA and RNA
d. Neither DNA nor RNA
Answer: c. Both DNA and RNA
3. What is the outer protein coat of a virus called?
a. Capsid
b. Envelope
c. Membrane
d. Shell
Answer: a. Capsid
4. How do viruses replicate within a host cell?
a. Binary fission
b. Mitosis
c. Lytic and lysogenic cycles
d. Meiosis
Answer: c. Lytic and lysogenic cycles
5. Which of the following is not a characteristic of living organisms but applies to viruses?
a. Metabolism
b. Reproduction
c. Response to stimuli
d. Cellular structure
Answer: d. Cellular structure
6. What is the purpose of the viral envelope?
a. Protection of the nucleic acid
b. Facilitation of attachment to host cells
c. Regulation of viral replication
d. Storage of genetic information
Answer: b. Facilitation of attachment to host cells
7. Which of the following is a viral disease in humans caused by a retrovirus?
a. Influenza
b. Measles
c. HIV/AIDS
d. Hepatitis B
Answer: c. HIV/AIDS
8. How do bacteriophages primarily infect bacterial cells?
a. Fusion with the host cell membrane
b. Injection of genetic material
c. Endocytosis
d. Direct absorption through the cell wall
Answer: b. Injection of genetic material
9. What is the name of the process through which a virus acquires an envelope from its host cell membrane during exit?
a. Budding
b. Lysis
c. Fusion
d. Endocytosis
Answer: a. Budding
10. Which of the following is an example of a DNA virus?
a. Influenza virus
b. Rhinovirus
c. Herpes simplex virus
d. HIV
Answer: c. Herpes simplex virus
11. What is the primary function of the reverse transcriptase enzyme in retroviruses?
a. Transcription of viral RNA to DNA
b. Translation of viral RNA into protein
c. Replication of viral RNA
d. Integration of viral DNA into the host genome
Answer: a. Transcription of viral RNA to DNA
12. Which of the following is the genetic material of influenza viruses?
a. DNA
b. RNA
c. Both DNA and RNA
d. Neither DNA nor RNA
Answer: b. RNA
13. In the lytic cycle of a bacteriophage, what is the outcome for the host cell?
a. Integration of viral DNA into the host genome
b. Lysis and death of the host cell
c. Establishment of a persistent infection
d. Formation of a provirus
Answer: b. Lysis and death of the host cell
14. Which part of the host cell do enveloped viruses obtain during the process of budding?
a. Cytoplasm
b. Nucleus
c. Cell membrane
d. Mitochondria
Answer: c. Cell membrane
15. What is the primary function of the capsid in a virus particle?
a. Facilitating attachment to host cells
b. Protecting the viral genome
c. Enabling viral replication
d. Facilitating viral transcription
Answer: b. Protecting the viral genome
16. Which of the following is a DNA virus that can cause cancer in humans?
a. Human papillomavirus (HPV)
b. Influenza virus
c. Epstein-Barr virus (EBV)
d. Dengue virus
Answer: c. Epstein-Barr virus (EBV)
17. What is the main target of antiretroviral drugs used in the treatment of HIV/AIDS?
a. Viral capsid
b. Reverse transcriptase
c. Viral envelope
d. Capsomeres
Answer: b. Reverse transcriptase
18. Which of the following is an example of a retrovirus?
a. Herpes simplex virus
b. Hepatitis C virus
c. Human immunodeficiency virus (HIV)
d. Rotavirus
Answer: c. Human immunodeficiency virus (HIV)
19. What is the process by which a prophage is formed in the lysogenic cycle of a bacteriophage?
a. Integration of viral DNA into the host genome
b. Lysis of the host cell
c. Budding of new viral particles
d. Transcription of viral RNA
Answer: a. Integration of viral DNA into the host genome
20. Which type of virus is more likely to undergo latency and establish persistent infections in the host?
a. DNA viruses
b. RNA viruses
c. Enveloped viruses
d. Retroviruses
Answer: a. DNA viruses
21. Which of the following statements is incorrect?
1. Viroids are smaller than viruses.
2. RNA was found to be free in viroid.
3. The RNA of the viroid is of high molecular weight.
4. In 1971, T.O. Diener discovered it.
Answer- 3, The RNA of the viroid is of high molecular weight.
22. Which of the following diseases is not caused by Prions?
1. In cattle, bovine spongiform encephalopathy (BSE) occurs
2. Cr-Jacob disease (CJD) in humans.
3. Mad cow disease in cattle
4. Potato Spindle Tuber disease
Answer- 4, Potato Spindle Tuber disease
23. Which of the following pathogenic disease could have the symptoms like mosaic formation, leaf rolling and curling, yellowing and vein clearing, dwarfing, and stunted growth?
1. Viral
2. Bacterial
3. Fungal
4. Deficiency syndrome.
Answer- 1, Viral
24. Interferons curb infection of
1. Fungi
2. Bacteria
3. cancer
4. None of these
Answer- 4, None of these
25. First time a virus has been synthesized as a non-living crystal
1. Pox virus
2. Flu virus
3. Tobacco mosaic virus
4. Bacteriophage
Answer- 3, Tobacco mosaic virus
26. Causative of Chickenpox is
1. Bacteriophage T-2
2. varicella virus
3. sv-40 virus
4. Adenovirus
Answer- 2, Varicella virus
27. The causes of the “potato mosaic” disease are
1. Fungi
2. Bacteria
3. Virus
4. Mycoplasma
Answer- 3, Virus
28. Which of the following shows the coiled strands of RNA and capsomeres?
1. Poliovirus
2. Tobacco mosaic virus
3. Measles virus
4. Retrovirus
Answer- 2, Tobacco mosaic virus
29. The rabies virus consists of
1. Single-stranded RNA
2. Double-stranded RNA
3. Single-stranded DNA
4. Double-stranded DNA
Answer- 1, Single-Stranded RNA
30. The term “virion is used for
1. Mycoplasma colony
2. Group of viruses
3. Nostoc colony
4. Single virus
Answer- 4, Single Virus
31. The genetic material in viruses is
1. Only RNA
2. Only DNA
3. RNA and DNA both
4. RNA or DNA i.e. one nucleic acid in a virus
Answer- 4, RNA or DNA i.e. one nucleic acid in a virus
32. Each capsomere of TMV contains amino acids whose number is
1. 158
2. 185
3. 815
4. 581
Answer- 1, 158
33. This is a communicable disease
1. Rabies
2. Cancer
3. Alkaptonuria
4. Phenylketonuria
Answer- 1, Rabies
34. Hydrophobia or rabies is a disease caused by
1. Protozoan
2. Nematode
3. virus
4. Helminth
Answer- 3, virus
35. Viruses did not find a place in classification because —
1. There is no cellular structure in them
2. They can be crystallized
3. There is no cellular structure in them
4. All of the above
Answer- 4, All of the above