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

Quinolones inhibit bacterial growth by targeting

  1. DNA replication

  2. mRNA translation

  3. RNA polymerase

  4. active transport of nutrients into the cell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quinolones are a class of antibiotics that inhibit bacterial DNA gyrase and topoisomerase IV, thereby blocking DNA replication.

Multiple choice

Listerine was originally...

  1. A household cleaner

  2. Mouthwash for dogs

  3. Detergent

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

Listerine was developed in the late 19th century and was initially marketed as a powerful surgical antiseptic and a general household cleaner, including uses for floor scrubbing and treating cuts.

Multiple choice biology interdependence of organism and the environment natural cycles and resources constituents of air medicinal use of microorganism

Penicillin inhibits bacterial multiplication because it

  1. Checks RNA synthesis

  2. Checks DNA synthesis

  3. Destroys chromatin

  4. Inhibits cell wall formation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Antibiotics are chemical substances, which are produced by some microbes and kill or retard the growth of other ( disease-causing ) microbes. Penicillin was the first antibiotic discovered. Penicillin inhibits bacterial growth by inhibiting cell wall formation, hence, killing the bacteria.

So, the correct answer is 'Inhibits cell wall formation'

Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

Alexander Fleming discovered penicillin in 1928, while working with

  1. Streptomyces

  2. Bacteria (Staphylococcus)

  3. Penicillium notatum

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

In 1928, Alexander Fleming was investigating the properties of Staphylococci. One day, he observed that the culture of Staphylococci was contaminated with fungus and that colonies of the culture surrounding the fungus had been destroyed. 
Fleming grew the mold in a pure culture and found that it produce a substance that killed a number of disease-causing bacteria. He identified the mold (fungus) as being from the Penicillium genus and named the substance it released Penicillin. He investigated its positive antibacterial effect on many organisms and noticed that it affected bacteria such as Staphylococci and many other Gram-positive pathogens that cause scarlet fever, pneumonia, meningitis, diphtheria but not typhoid fever caused by Gram-negative bacteria.

Therefore, the correct answer is option B.

Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

The cultures of Alexander Fleming consisted of

  1. Streptococcus

  2. Staphylococcus

  3. Bacillus

  4. Clostridium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Alexander Fleming was working with a bacteria to study the action of lysozyme and its role in the fighting of the infection in the human body.
  • The bacterial culture that he was working on was of Staphylococcus 
  • Due to some fault, the bacterial culture Fleming was working on developed a fungal infection of Penicillium notatum which inhabited the growth of the bacteria in the culture.
  • The secretion which was released by the fungus was called mold juice by Fleming but later he named it as penicillin after the name of the organism which secretes it.
  • So the answer Staphylococcus is correct.
Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

Penicillin will be unaffective against ___________________.

  1. Mycoplasma, Slime moulds and Psedomonas

  2. Staphyloccus, Mycoplasma & Animal cell

  3. Slime moulds, Aspegillus & Psedomonas

  4. Mycoplasma, Animal cell & Slime moulds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Penicillin targets the synthesis of peptidoglycan in bacterial cell walls. Mycoplasma lacks a cell wall, slime molds are eukaryotes, and Pseudomonas has a different cell wall structure/permeability, making them resistant to penicillin.

Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

Fleming discovered Penicillin from

  1. Penicillium notatum

  2. P. roqueforti

  3. P. camemberti

  4. P. chryaogenum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Discovery of penicillin antibiotic by Fleming was an accidental discovery.
  • Fleming was working with different bacterial strains to study the effect of lysozyme in fighting of bacterial infection in human body.
  • In his lab there were many petri dish containing different strains of bacteria, he observed that one of the petridishes containing the strain for bacteria  Staphylococcus was infected by the growth of a fungus
  • This fungus growing along with the bacterial colony inhibited the growth of the bacterial colony
  • On further observation Fleming saw that the chemical substances secreted by the mold inhibited the bacterial growth. He named it Penicillin after the name of the organism ie Penicillium notatum
  • So, the correct answer is Penicillium notatum 
Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

In 1928, a scientist discovered the first effective antibiotic. Scientist and antibiotics are

  1. Fleming - Streptomycin

  2. Fleming - Penicillin

  3. Waksman - penicillin

  4. Waksman - streptomycin.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • In September 1928 when Alexander Fleming observed his Petri dishes of the bacterial culture he notice that the culture of bacteria Staphylococcus has a mold growing over it which has inhabited its growth in that area.
  • Upon observing he found that the mold was a strain of fungus Penicillium notaum and its was secreting some substance which inhibited the growth of the bacteria.
  • He named it penicillin after the organism from which it is secreted.
  • So the answer Alexander Fleming who discovered the first antibiotic penicillin is correct.
Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

The culture and fungal invader in discovery of penicillin by Alexander Fleming are

  1. Vibrio cholerae and Penicillium requeforti

  2. Staphylococcus aureus and Penicillium notatum

  3. Eacherichia coli and Penicillium chrysogenum

  4. Clostridium tetani and Penicillium chrysogenum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The discovery of Penicillin was a case of serendipity and it was observed on a culture plate of Staphylococcus aureus that was contaminated by a fungus species. 

So, the correct option is "Staphylococcus aureus and Penicillium notatum".

Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

Which of the following statement is incorrect about antibiotics?

  1. Coined by Waksman (1942)

  2. Produced by microorganisms

  3. Produce allergy in some persons

  4. Cure all diseases
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Antibiotic is a medicine which inhibits the growth of microbes. This term was coined by Selman Waksman. They are produced by many bacteria, fungi, and other microorganisms. Some of them increase the activity of mast cell resulting into allergy. They are specific for the disease.

So, the correct answer is 'Cure all diseases'

Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

Which of the following statements regarding antibiotics is not correct?


i) Antibiotic is the attenuated microorganisms which in small concentrations, can kill or retard the growth of other harmful microorganisms.
ii) Penicillin was the first antibiotic to be discovered by Alexander Fleming (1928) while working on bacterium Staphylococcus aureus.
iii) The full potential of penicillin as an effective antibiotic was established by Ernest Chain and Howard Florey.
iv) Fleming, Chain, and Florey were awarded the Nobel Prize in 1945.

  1. (i) Only

  2. (iii) Only

  3. (ii) and (iv)

  4. (i), (iii) and (iv)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Antibiotics are antimicrobials that are released by bacteria, fungi or molds naturally or are synthesized artificially that are capable of killing or inhibiting competing microbial species. They are therefore antimicrobial substances and not entire microorganisms that are used. 
  • In 1928 penicillin, the first true antibiotic was discovered by Alexander Fleming from colonies of Staphylococcus bacteria. However, its full potential as an antibiotic was established by Florey and Chain. Howard Florey, Ernst Chain, and Sir Alexander Fleming received the Nobel prize for their work on penicillin in 1945. 
  • So, the correct answer is '(i) only'.