1. In which of the following infection the infecting dose of virus is small?
a) Acute
b) Persistent
c) Null
d) Subclinical
Explanation: The infection in which the infecting dose of virus is small and the virus goes through many rounds of replication is called acute infection and this infection spreads from first infected cells to new susceptible cells. It is analog to acutely cytopathogenic infections.
2. Influenza virus infects _______________
a) liver
b) respiratory system
c) kidney
d) heart
Explanation: Influenza virus infects the respiratory system and causes fever, aching, catarrh, etc. Whereas the hepatitis virus infects the liver. This specificity is achieved largely through the presence of cell receptors on only certain cells in the body.
3. Which of the following is also known as a silent infection?
a) Acute
b) Persistent
c) Tumorigenic
d) Subclinical
Explanation: Subclinical infections are also known as silent infections or inapparent infections. They are the most common infections and no signs and symptoms occur of the disease. These are the same as acute infections.
4. Human Papillomavirus causes the cancer of ___________
a) liver
b) lymphoid tissue
c) cervix
d) mouth
Explanation: Human papillomavirus (HPV) is a group of viruses that causes cervical cancer. HPV infection also passes through the skin to skin contact. It is most common in the United States.
5. Cell lysis is associated with necrosis.
a) True
b) False
Explanation: Apoptosis contrasts with cell lysis or necrosis where the cells disintegrate and its contents are released. The cells which undergo necrosis are inflammatory as the necrotic products are inflammatory in the whole animal.
6. T cells are the main defense against primary infections.
a) True
b) False
Explanation: T cells are the main defense against primary infections. T cells in particular CD8+ cytotoxic T cells and antibodies are the main defense against primary infections.
7. Which of the following virus causes the cancer of lymphoid tissue of the jaw?
a) HBV
b) HPV
c) EBV
d) HIV
Explanation: Epstein-Barr virus (EBV), a herpes virus, causes the cancer of lymphoid tissue of jaw which is also called Burkitt’s lymphoma. It also causes nasopharyngeal carcinoma.
8. Which of the following antibody is present in breast milk?
a) IgG
b) IgA
c) IgE
d) IgM
Explanation: IgA antibody is present in breast milk. It helps the infants to fight against microbes and several infectious agents. Breast milk is preferred for infants because cow milk does not contain antibodies.
9. Which of the following viruses are best known for latent infections?
a) Rhinovirus
b) Herpesvirus
c) Poliovirus
d) HIV
Explanation: Herpes virus is a group of viruses that are best known for latent infections. They infect a wide range of hosts including humans. Once the infection is established the virus remains associated with the host for the remainder of its life.
10. The bacteria carrying the phage DNA are called ________________
a) prophage
b) temperate phage
c) lysogens
d) bacteriophage
Explanation: The bacteria which carry the phage DNA are called lysogens or lysogenic bacteria. It is a bacterial cell that can produce and transfer the ability to produce a phage.