Biology

Antibiotics and Immunity

974 Questions

Prepare for your science sections with these questions on antibiotics and immunity. The hub covers various classes of antibiotics, their sources, and mechanisms of microbial resistance. It also addresses the human antiviral response.

Antibiotic classes and sourcesMicrobial resistance mechanismsAntiviral proteinsDisease treatments

Antibiotics and Immunity Questions

Multiple choice

In a Gram-positive cell wall, the structure responsible for providing antigenicity to the organism is

  1. lipoteichoic acid

  2. teichoic acid

  3. lipopolysaccharide

  4. peptide chain
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lipoteichoic acid confers antigenic properties to Gram-positive organisms. It stimulates specific immune responses and is released from the bacterial cells mainly after bacteriolysis is induced by lysozymes, cationic peptides from leucocytes or beta-lactam antibiotics.

Multiple choice

Match the entries:

 
Column I Column II
P. Bacitracin 1. Inhibition of protein biosynthesis
Q. Chloramphenicol 2. Inhibition of bacterial cell wall biosynthesis
R. Griseofulvin 3. Inhibition of cell metabolism
S. Isoniazid 4. Inhibition of nucleic acid biosynthesis

  1. P - 1; Q - 2; R - 3; S - 4

  2. P - 1; Q - 3; R - 2; S - 4

  3. P - 2; Q - 1; R - 4; S - 3

  4. P - 2; Q - 3; R - 4; S - 1

  5. P - 3; Q - 1; R - 4; S - 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacitracin innhibits bacterial cell wall biosynthesis. Chloramphenicol acts by inhibition of protein biosynthesis.

Multiple choice

Identify the false statement.

  1. Cephalothin is a first-generation cephalosporin.

  2. Penicillin G is effective against gram-positive bacteria.

  3. Isoniazid inhibits incorporation of mycolic acid into cell wall of Mycobacterium spp.

  4. Rifampin inhibits synthesis of mRNA.

  5. Nalidixic acid acts by inhibiting DNA synthesis.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Isoniazid inhibits synthesis of mycolic acid component of cell wall of Mycobacterium spp.

Multiple choice

Brefeldin A is a lactone antibiotic produced by fungal organisms such as Eupenicillium brefeldianum. It is used to check the activity of which of the following cell organelles?

  1. Mitochondria

  2. Nucleus

  3. Golgi apparatus

  4. Endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Brefeldin A is used to test Golgi function. It blocks the activation of some ADP-ribosylation factors (ARFs) which regulate vesicular trafficking through the binding of COPs to the Golgi. Thus, treatment with Brefeldin A disrupts the secretion pathway.

Multiple choice

Which of the following is a culture medium for Neisseria?

  1. Eaton's agar

  2. Thayer-Martin agar

  3. Bismuth sulphite agar

  4. Bordet-Gengou agar

  5. Löwenstein-Jensen medium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thayer-Martin agar, a Mueller-Hinton agar with 5% chocolate sheep blood and antibiotics, is used for culturing and primarily isolating pathogenic Neisseria bacteria.

Multiple choice

Which of the following is effective against tuberculosis?

  1. Pencillin

  2. Chloromycetin

  3. Terramycin

  4. Streptomycin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Streptomycin is an antibiotic effective against tuberculosis, discovered by Selman Waksman in 1943. Penicillin is not effective against TB. Chloromycetin (chloramphenicol) treats bacterial infections but not TB. Terramycin (oxytetracycline) is also ineffective against tuberculosis.