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 biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Why do antibiotics kill bacteria but not viruses ? 

  1. Antibiotics stimulate the immune system against bacteria but not viruses

  2. Viruses have a ways of blocking antibiotics

  3. Viruses are too small to be affected by antibiotics

  4. Viruses do not have a metabolism
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Bacteria (except in spore stage) must be continuously metabolically active most of the time and thus can be cured at any time. Viruses are metabolically inert until they got a host cell and thus they are not susceptible to the actions of antivirals until then. An exception would be drugs that block viral adhesion to host cells, thus preventing their entry.
  • The virus often hijacks host genes, thus their protein can be closely related to host proteins. So it is difficult to distinguish between host and virus proteins.
  • The virus does not have a cell wall as bacteria. Antibiotics stop the making of a cell wall in bacteria. Thus they remain unaffected by antibiotics.

So the correct answer is 'Viruses do not have a metabolism'.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

For minor troubles such as cold, antibiotics should not be consumed because

  1. They can damage intestinal wall.

  2. They can create antibiotic resistant bacteria in the future.

  3. Both A and B.

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

Antibiotics should not be used for minor troubles like cold because some pathogenic bacteria could develop resistance to the action of this antibiotic. And on the excessive use of antibiotic, they can cause damage to the beneficiary intestinal micro-organisms. So, the correct answer is option B.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Which among the following is an antibiotic?

  1. Sodium bicarbonate

  2. Streptomycin

  3. Alcohol

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

Antibiotics are the chemicals that kill or inhibit the growth of bacteria and are used to treat bacterial infections. They either prevent the bacterial cells from multiplying.

Streptomycin is an antibiotic drug which hinders the reproductive pathway of the plant.
So, the correct answer is option B.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Which among the following is not an antibiotic?

  1. Citric acid

  2. Streptomycin

  3. Cephalosporin

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

  • Streptomycin is an antibiotic used in the treatment of bacterial infections like tuberculosis, endocarditis, brucellosis, plague, rat bite fever, etc. It is a broad spectrum antibiotic.
  • Cephalosporin is a beta-lactam antibiotic. It is used in the treatment of bacterial infections like respiratory tract infections, skin infections, urinary tract infections.
  • Griseofulvin is an antifungal antibiotic. It is used in the treatment of skin infections like ringworm, athlete's foot, infections of the scalp, fingernails, etc.
Thus, the correct answer is 'Citric acid.'

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

The chemicals released by bacteria, which kills other bacteria are

  1. Antibiotics

  2. Antibodies

  3. Antigens

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

Antibiotic is a chemical which is released by a bacteria and inhibits the growth of other bacteria. It acts by either killing bacteria or preventing their reproduction. 

Thus, the correct answer is 'Antibiotics.'

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

An antibiotic, which is active against fungi is

  1. Neomycin

  2. Terramycin

  3. Polyenes

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

Antibiotics are antimicrobial substances produced by microorganisms. They are used in the treatment of bacterial infections. Examples of antibiotics include Neomycin, terramycin, Streptmomycin. Polyenes are antifungal antibiotics produced by bacterium Streptomyces species which are used to treat fungal infections. They act by changing the fungal cell membrane by complexing with sterols.

Thus, the correct answer is 'Polyenes.'

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Broad spectrum antibiotics are the ones which attack

  1. Pathogens as well as hosts

  2. A wide range of pathogens

  3. Only a pathogen

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

Broad spectrum antibiotics are effective against a wide range of both Gram-positive and Gram-negative bacteria, rather than being limited to a single type or specific pathogen.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Mode of action of Novobiocin is

  1. Induces abnormal protein synthesis

  2. Inhibits DNA polymerisation

  3. Interferes with protein synthesis

  4. Inhibits cell wall synthesis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Novobiocin is an aminocoumarin antibiotic that inhibits bacterial growth by binding to the ATP-binding site of the DNA gyrase subunit B, effectively inhibiting DNA replication and supercoiling.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

The molecular structure of penicillin antibiotic is

  1. Macrocyclic lactone

  2. Glycoside linkage in amino sugar
  3. $\beta$-lactam ring

  4. Polyaena and nonpolyaene
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Penicillin is obtained from Penicillium chrysogenum. Penicillin is a secondary metabolite of certain species of Penicillium and is produced when the growth of the fungus is inhibited by stress. Its structure contains β- lactam ring with a molecular structure of 339.4 g/mol. It was discovered by Alexander Fleming.

So, the correct answer is 'β- lactam ring'

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Which of the following antibiotics kills bacterial cells by inhibiting the polymerisation of peptidoglycans?

  1. Aminoglycoside

  2. Fluoroquinolones

  3. Quinine

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

Penicillin is a secondary metabolite of certain species of Penicillium and is produced when the growth of the fungus is inhibited by stress. It is not produced during active growth. Production is also limited by feedback in the synthesis pathway of penicillin. It was discovered by Alexander Fleming.

So, the correct option is 'Penicillin.

Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Which one of the following is a antifungal antibiotic?

  1. Streptomycin

  2. Aureomycin

  3. Griseofulvin

  4. Chloromycetin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
1. Streptomycin is an antibacterial antibiotic.
2. Aureomycin is a brand name of medication included in antiinfectives and antiseptics.
3. Griseofulvin is an effective antifungal medication used to treat infections of skin, scalp, nails etc.so it is used to treat only fungal infections.
4. Chloromycetin is an effective medicine used for the treatment of serious infections caused by bacteria only.
So, the correct answer is 'Griseofulvin'.
Multiple choice biology the world of microbes medicinal use of microorganisms use of microorganisms in medicine vaccines

Streptomycin is effective for treatment of pathogens which are 

  1. Gram $(+)$ bacteria
  2. Gram $(-)$ bacteria

  3. Both A and B

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

Streptomycin is an antibiotic, a medicine used to inhibit the growth of microbes. Streptomycin is a broad spectrum antibiotic which works against both gram negative and gram-positive bacteria.

So, the correct answer is 'Both A and B'