Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

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

Identify a fungus with medicinal importance.

  1. Penicillium

  2. Cercospora

  3. Agaricus

  4. Saccharomyces
Reveal answer Fill a bubble to check yourself
A 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.

So, the correct option is 'Penicillium'.

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

Microorganisms are our friends and foes. Some of them are useful for us while some of them are harmful. From the given list sort out useful and harmful actions of microorganisms.
Production of antibiotics, food spoiling, curd preparation, vaccine production, citrus canker.

  1. Useful: Curd preparation, citrus canker, production of antibioticsHarmful: Food spoiling, vaccine production

  2. Useful: Production of antibiotics, curd preparation, vaccine productionHarmful: Food spoiling, citrus canker

  3. Useful: Citrus canker, vaccine production, curd preparationHarmful: Food spoiling, production of antibiotics

  4. Useful: Vaccine production, curd preparationHarmful: Food spoiling, citrus canker, production of antibiotics
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
An antibiotic is a chemical substance that inhibits the growth of bacteria. They hinder the reproductive cycle of the bacteria inside the body of the host.
Lactobacillus is a genus of bacteria, which can convert sugars into lactic acid by means of fermentation. 
A vaccine is a biological preparation that provides active acquired immunity to a particular disease. It has killed or weakened suspension of microorganism which generates the immune response.
Citrus canker is a disease affecting citrus species caused by the bacterium Xanthomonas axopods. The infection causes lesions on the leaves, stems, and fruit of citrus trees, including lime, oranges, and grapefruit. 

Micorganism like fungus releases toxins which spoils the food.
So, the correct answer is option B.