Biology

Antibiotics and Immunity

859 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

Polymorphonuclear neutrophils attack bacteria

  1. by phagocytosis

  2. exclusively by oxygen-dependent mechanisms

  3. exclusively by oxygen-independent mechanisms

  4. by secreting complement

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

The ability to ingest bacteria and killing them is a major feature of these professional phagocytic cells. Loss of neutrophils renders the host very susceptible to overwhelming infection.

Multiple choice

The first antibiotic was

  1. penicillin

  2. streptomycin

  3. tetramysin

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Alexander Fleming discovered penicillin in 1928, and it is widely recognized as the first true antibiotic used in medicine.

Multiple choice

Antibiotic can

  1. inhibit the pathogen

  2. destroy the pathogen

  3. both 1 and 2

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Antibiotics are designed to either inhibit the growth of bacteria (bacteriostatic) or kill the bacteria directly (bactericidal).

Multiple choice

A microorganism killing substance which is harmless for a living tissue is a/an

  1. disinfectant

  2. antiseptic

  3. antibiotic

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Antiseptics can be used to kill microorganisms  or prevent their multiplication. Antiseptics do not harm the living tissues. Therefore, they can be applied on cuts and wounds. Dettol, cetavelon, savlon, acriflavin, gentian-violet, mercuro chrome, boric acid and potassium permanganate are some examples.

 

Multiple choice

Which of the following is not an antibiotic?

  1. Chloramphenicol

  2. Streptomycin

  3. Cetavelon

  4. Tetracyclines

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

It is an antiseptic. An antiseptic is used to kill bacteria or prevent their multiplication. Antiseptics do not harm the living tissues. Therefore, they can be applied on cuts and wounds.

Multiple choice

Antibiotics are

  1. chemicals

  2. matters

  3. molecules

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Antibiotics are chemical substances produced by microorganisms or synthesized to inhibit the growth of or kill bacteria.

Multiple choice

Antibiotics kill the microbes by blocking their

  1. growth

  2. life

  3. Biochemical pathways

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

Antibiotics work by targeting specific cellular processes in bacteria, such as cell wall synthesis or protein production, which are referred to as biochemical pathways.

Multiple choice

Antibiotics _________ kill viruses.

  1. can

  2. cannot

  3. always

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Antibiotics are designed to target bacterial structures or pathways. Viruses have different structures and replicate differently, so antibiotics are ineffective against them.

Multiple choice

Antibiotic destroy __________.

  1. bacteria

  2. other microbes

  3. both 1 and 2

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Antibiotics are antimicrobial substances that act against bacteria. They can target various types of bacteria and other microbes, making both 1 and 2 the correct scope.

Multiple choice

Bordeaux mixture is an

  1. antibiotic

  2. organochlorine

  3. organophosphate

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

Bordeaux mixture is a combination of copper sulfate and lime, used as an inorganic fungicide to control fungal diseases in plants.

Multiple choice

What is tetracycline?

  1. An anti-plague drug

  2. A preservative

  3. A pest killer

  4. An air purifier
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tetracycline is a broad-spectrum antibiotic discovered in 1948, used to treat various bacterial infections. While it can be used to treat plague (caused by Yersinia pestis), it is not exclusively an 'anti-plague drug' - it's used for many conditions including pneumonia, acne, urinary tract infections, and more. Among the given options, only A is in the correct category (drug/medicine), though the description is imprecise. The other options are completely incorrect.

Multiple choice

Compared to gram-negative bacteria, gram-positive bacteria

  1. retain the violet dye rather than the red dye

  2. are more resistant to antibiotics

  3. have less peptidoglycan

  4. have more complex cell walls
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through a microscope.

Multiple choice

It is most difficult to prepare drugs against

  1. bacteria

  2. virus

  3. fungi

  4. protozoa
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Viruses are intracellular parasites that use the host's cellular machinery to replicate, making it very difficult to design drugs that target the virus without harming the host cells. Bacteria, fungi, and protozoa have distinct metabolic pathways that are easier to target.