Multiple Choice Questions
Biology: Microbiology and Immunology
Topic: Microbiology and Immunology
Grade: 11
Question 1:
Which of the following is NOT a characteristic of prokaryotic cells?
a) They lack a nucleus
b) They have a cell wall
c) They can perform photosynthesis
d) They have membrane-bound organelles
Answer: d) They have membrane-bound organelles
Explanation: Prokaryotic cells are simple cells that lack a nucleus and membrane-bound organelles. They have a cell wall, which provides structural support. Examples of prokaryotic cells include bacteria. Eukaryotic cells, on the other hand, have a nucleus and membrane-bound organelles.
Question 2:
Which of the following is an example of a gram-positive bacterium?
a) Escherichia coli
b) Streptococcus pyogenes
c) Salmonella enterica
d) Mycobacterium tuberculosis
Answer: b) Streptococcus pyogenes
Explanation: Gram-positive bacteria retain the crystal violet stain and appear purple under a microscope. Streptococcus pyogenes is a gram-positive bacterium that causes strep throat. Gram-negative bacteria, such as Escherichia coli and Salmonella enterica, do not retain the stain and appear pink. Mycobacterium tuberculosis is an acid-fast bacterium.
Question 3:
Which of the following is an example of passive immunity?
a) Receiving a vaccine
b) Breastfeeding
c) Contracting a disease and recovering
d) Transfusion of blood from a donor
Answer: b) Breastfeeding
Explanation: Passive immunity is the transfer of antibodies from one individual to another. Breastfeeding provides newborns with maternal antibodies, offering them temporary protection against diseases. Vaccination and contracting a disease and recovering both result in active immunity, where the individual\’s immune system produces its own antibodies. Transfusion of blood from a donor does not confer immunity.
Question 4:
Which of the following is an example of a bactericidal antibiotic?
a) Penicillin
b) Tetracycline
c) Erythromycin
d) Chloramphenicol
Answer: a) Penicillin
Explanation: Bactericidal antibiotics kill bacteria directly by interfering with their cell wall synthesis, protein synthesis, or DNA replication. Penicillin is a bactericidal antibiotic that inhibits cell wall synthesis. Tetracycline, erythromycin, and chloramphenicol are examples of bacteriostatic antibiotics, which inhibit bacterial growth but do not kill them.
Question 5:
Which of the following is NOT a characteristic of viruses?
a) They can replicate outside of a host cell
b) They are obligate intracellular parasites
c) They can infect all types of organisms
d) They possess genetic material
Answer: a) They can replicate outside of a host cell
Explanation: Viruses are obligate intracellular parasites, meaning they cannot replicate outside of a host cell. They are dependent on host cells to replicate and produce more virus particles. Viruses can infect all types of organisms and possess genetic material, which can be either DNA or RNA.
Question 6:
Which of the following is the main function of the lymphatic system?
a) Producing red blood cells
b) Transporting oxygen
c) Filtering blood
d) Defending against pathogens
Answer: d) Defending against pathogens
Explanation: The lymphatic system plays a crucial role in the body\’s immune response. It helps defend against pathogens by producing and transporting white blood cells, filtering lymph (a fluid similar to blood plasma), and trapping and removing foreign substances. The production of red blood cells occurs in the bone marrow, and the transport of oxygen is primarily carried out by the circulatory system.
Question 7:
Which of the following is an example of an autoimmune disease?
a) Diabetes mellitus
b) Influenza
c) Tuberculosis
d) Malaria
Answer: a) Diabetes mellitus
Explanation: Autoimmune diseases occur when the immune system mistakenly attacks the body\’s own cells and tissues. Diabetes mellitus is an example of an autoimmune disease, where the immune system attacks the insulin-producing cells in the pancreas. Influenza, tuberculosis, and malaria are infectious diseases caused by pathogens.
Question 8:
Which of the following is responsible for the production of antibodies?
a) B cells
b) T cells
c) Macrophages
d) Natural killer cells
Answer: a) B cells
Explanation: B cells are a type of white blood cell that are responsible for the production of antibodies. When activated by an antigen, B cells differentiate into plasma cells, which secrete antibodies. T cells are involved in cell-mediated immunity, macrophages are phagocytic cells that engulf and destroy pathogens, and natural killer cells are involved in the innate immune response.
Question 9:
Which of the following is an example of an opportunistic infection?
a) Influenza
b) Tuberculosis
c) Candidiasis
d) Malaria
Answer: c) Candidiasis
Explanation: Opportunistic infections are infections caused by pathogens that take advantage of a weakened immune system. Candidiasis, caused by the yeast Candida, is an example of an opportunistic infection that commonly occurs in individuals with compromised immune systems. Influenza, tuberculosis, and malaria are infectious diseases caused by specific pathogens.
Question 10:
Which of the following is an example of a live attenuated vaccine?
a) Hepatitis B vaccine
b) Measles vaccine
c) Tetanus vaccine
d) Influenza vaccine
Answer: b) Measles vaccine
Explanation: Live attenuated vaccines contain weakened forms of the infectious agent that can still replicate in the body but cause a milder form of the disease. The measles vaccine is an example of a live attenuated vaccine. Hepatitis B, tetanus, and influenza vaccines are either inactivated or subunit vaccines that do not contain live organisms.
Question 11:
Which of the following is an example of a vector-borne disease?
a) Chickenpox
b) Lyme disease
c) Pneumonia
d) Food poisoning
Answer: b) Lyme disease
Explanation: Vector-borne diseases are transmitted to humans through the bite of an infected arthropod, such as a mosquito or tick. Lyme disease is an example of a vector-borne disease, transmitted by the bite of a deer tick infected with the bacterium Borrelia burgdorferi. Chickenpox, pneumonia, and food poisoning are not typically transmitted through vectors.
Question 12:
Which of the following is involved in the cell-mediated immune response?
a) Antibodies
b) Cytokines
c) Complement proteins
d) Cytotoxic T cells
Answer: d) Cytotoxic T cells
Explanation: The cell-mediated immune response involves the activation and proliferation of cytotoxic T cells, which can directly kill infected or cancerous cells. Antibodies are involved in the humoral immune response, cytokines are signaling molecules that regulate immune responses, and complement proteins are part of the innate immune system.
Question 13:
Which of the following is an example of an antiviral drug?
a) Penicillin
b) Azithromycin
c) Acyclovir
d) Streptomycin
Answer: c) Acyclovir
Explanation: Antiviral drugs are used to treat viral infections by inhibiting viral replication. Acyclovir is an antiviral drug commonly used to treat herpes simplex virus infections. Penicillin, azithromycin, and streptomycin are antibiotics used to treat bacterial infections.
Question 14:
Which of the following is an example of an antigen-presenting cell?
a) B cell
b) T cell
c) Macrophage
d) Natural killer cell
Answer: c) Macrophage
Explanation: Antigen-presenting cells (APCs) are cells that display antigens on their surface to activate other immune cells. Macrophages are professional APCs that engulf and process pathogens, presenting the antigens to helper T cells. B cells are involved in antibody production, T cells are involved in cell-mediated immunity, and natural killer cells are part of the innate immune response.
Question 15:
Which of the following is an example of a zoonotic disease?
a) HIV/AIDS
b) Ebola virus disease
c) Typhoid fever
d) Pneumonia
Answer: b) Ebola virus disease
Explanation: Zoonotic diseases are infections that can be transmitted between animals and humans. Ebola virus disease is an example of a zoonotic disease, with fruit bats being the natural reservoir. HIV/AIDS is a zoonotic disease that originated from chimpanzees, but it is primarily transmitted through human activities. Typhoid fever and pneumonia are not typically considered zoonotic diseases.