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

Which two organisms can be distinguished by using the antibiotic bacitracin?

  1. S. pyogenes from other beta hemolytic bacteria

  2. S. pyogenes from S. pneumoniae

  3. S. aureus from S. epidermis

  4. S. pyogenes from S. aureus
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacitracin is used to distinguish S. pyogenes from other β-hemolytic streptococci because S. pyogenes is sensitive to bacitracin and other beta hemolytic bacteria are resistant.

Multiple choice

Which of the following are susceptible to monobactams?

  1. Aerobic gram positive bacteria

  2. Anaerobic gram negative bacteria

  3. Aerobic gram negative bacteria

  4. Anaerobic gram positive bacteria
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Monobactams work only against aerobic gram negative bacteria, e.g. Neisseria, Pseudomonas etc.

Multiple choice

Match the antibiotics with the organisms that produce them:

Antibiotic Organism
1. Chlorotetracycline a. Streptomyces noursei
2. Streptomycin b. Streptomyces aureofaciens
3. Nystatin c. Streptomyces orientalis
4. Vancomycin d. Streptomyces griseus
  1. 1. Chlorotetracycline c. Streptomyces orientalis
    2. Streptomycin a. Streptomyces noursei
    3. Nystatin b. Streptomyces aureofaciens
    4. Vancomycin d. Streptomyces griseus
  2. 1. Chlorotetracycline a. Streptomyces noursei
    2. Streptomycin c. Streptomyces orientalis
    3. Nystatin d. Streptomyces griseus
    4. Vancomycin b. Streptomyces aureofaciens
  3. 1. Chlorotetracycline b. Streptomyces aureofaciens
    2. Streptomycin d. Streptomyces griseus
    3. Nystatin a. Streptomyces noursei
    4. Vancomycin c. Streptomyces orientalis
  4. 1. Chlorotetracycline a. Streptomyces noursei
    2. Streptomycin b. Streptomyces aureofaciens
    3. Nystatin c. Streptomyces orientalis
    4. Vancomycin d. Streptomyces griseus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct match. Chlorotetracycline is produced by S. aureofaciens, Streptomycin is produced by S. griseus, Nystatin is produced by S. noursei and Vancomycin is produced by S. orientalis.

Multiple choice

Which of the following organisms produces a potent exotoxin (in addition to an endotoxin) to manifest its infection?

  1. Pseudomonas aeruginosa

  2. Brucella suis

  3. Bordetella pertussis

  4. Neisseria meningitidis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pseudomonas aeruginosa produces a potent exotoxin (in addition to an endotoxin) to manifest its infection. The lethal exotoxin produced is called toxin A. It has a mechanism of action identical to that of diphtheria toxin.

Multiple choice

The medicine used for curing rabies is called:

  1. antibacterial

  2. antiviral

  3. antifungal

  4. antibodies

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rabies is caused by the rabies virus, which attacks the central nervous system. Therefore, treatment requires antiviral medications. Antibacterial drugs target bacteria, antifungal drugs target fungi, and antibodies are immune proteins produced by the body - none of these are effective against viral infections.

Multiple choice

______ were the first drugs to be used systematically for treatment and prophylaxis of bacterial infections in man.

  1. Sulfonamides

  2. Oxytetracyclines

  3. Desonides

  4. Xanthine derivatives

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sulfonamides were the first systematically used antibacterial drugs in humans, introduced in the 1930s before penicillin became widely available. They inhibit bacterial folic acid synthesis. The other options are incorrect - Oxytetracyclines are tetracycline antibiotics, Desonides is a corticosteroid, and Xanthine derivatives are bronchodilators.

Multiple choice

Which of the following species of penicillin is used only orally?

  1. Penicillin G

  2. Benzathine penicilline G

  3. Procaine penicillin G

  4. Penicillin V

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Penicillin V (phenoxymethylpenicillin) is the only penicillin listed that can be administered orally because it is acid-stable and survives gastric digestion. Penicillin G, Benzathine penicillin G, and Procaine penicillin G are all parenteral formulations given by injection as they are destroyed by stomach acid.

Multiple choice

Cefotaxime is the _______ cephalosporin.

  1. first generation

  2. second generation

  3. third generation

  4. fourt generation

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cefotaxime is a third-generation cephalosporin antibiotic. Third-generation cephalosporins have enhanced activity against gram-negative bacteria compared to earlier generations, while maintaining some gram-positive coverage. Cefotaxime is commonly used for serious infections like meningitis, septicemia, and respiratory tract infections.

Multiple choice

Which of the following antibiotics are derived from the members of genus Streptomyces?

  1. Penicillin, Streptomycin, Griseofulvin

  2. Chloramphenicol, Griseofulvin, Oxytetracycline

  3. Streptomycin, Chloramphenicol, Oxytetracycline

  4. Streptomycin, Oxytetracycline, Bacitracin

  5. Griseofulvin, Chloramphenicol, Penicillin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Streptomycin: Streptomyces griseus Chloramphenicol: Streptomyces venezuelae Oxytetracycline: Streptomyces rimosus All these antibiotics are derived from members of genus Streptomyces.

Multiple choice

EYCIN is an

  1. ointment for dissolving cataract

  2. eye-controlled interaction with computer

  3. acronym for the Interaction of European Youth Community

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice

The fatal effect of Penicillin in bacteria was discovered by

  1. Pasteur

  2. Koch

  3. Fleming

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

Alexander Fleming discovered the antibacterial properties of penicillin in 1928 when he observed that mold from the Penicillium fungus prevented bacterial growth in a petri dish. This accidental discovery revolutionized medicine.

Multiple choice

Assertion (A): Gram-positive bacteria are generally resistant to complement-mediated lysis. Reason (R): Thick peptidoglycan layer in Gram-positive bacteria prevents insertion of membrane attack complex into the inner membrane.

Directions: In the following question there are two statements, Assertion (A) and Reason (R), consider both the statements independently and mark your answers as under:

1. If A and R both are correct and R is correct explanation of A.
2. If A and R both are correct and R is not correct explanation of A.
3. If A is correct and R is incorrect.
4. If A is incorrect and R is correct.
5. If A and R both are incorrect.

  1. 1

  2. 2

  3. 3

  4. 4

  5. 5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is the correct answer. A and R both are correct and R is correct explanation of A. Gram-positive bacteria are generally resistant to complement-mediated lysis because thick peptidoglycan layer prevents insertion of membrane attack complex into the inner membrane.

Multiple choice

Which of the following sets represents selectable markers for Escherichia coli?

  1. Chloramphenicol, ampicillin, ranitidine

  2. Tetracycline, ranitidine, cimetidine

  3. Ampicillin, chloramphenicol, tetracycline

  4. Chloramphenicol, streptomycin, kanamycin

  5. Chloramphenicol, streptomycin, ranitidine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A gene whose expression allows one to identify cells that have been transformed or transfected with a vector containing the marker gene is known as a selectable marker which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants. Normally, the genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc. are considered as useful selectable markers for Escherichia coli. Hence, the set ‘ampicillin, chloramphenicol, tetracycline’ represents selectable marker for Escherichia coli.