Mycoplasma

Mycoplasma is a genus of bacteria that lacks a cell wall around its cell membranes. As a result of this trait, they are inherently resistant to drugs that attack cell wall production (like the beta-lactam antibiotics). It is possible for them to be parasitic or saprotrophic. Several species, including M. Pneumoniae, which causes “walking” pneumonia and other respiratory disorders, and M. Genitalium, which is thought to be involved in pelvic inflammatory diseases, are pathogenic in humans. Mycoplasma species are the tiniest bacterium known, capable of surviving without oxygen, and appear in a variety of forms. M. Genitalium, for example, is flask-shaped (approximately 300 x 600 nm), whereas M. Pneumoniae is more elongated (about 100 x 1000 nm). Animals are infected by hundreds of different mycoplasma species.

Q1. The smallest cells of mycoplasmas are around ______ in diameter.

1. 1 micrometre

2. 1 metre

3. 5 micrometre

4. 0.3 micrometre

Ans. Here the correct answer is option ‘d’ 0.3 micrometre. Mycoplasmas’ smallest cells are roughly 0.3 micrometres in diameter, and their plasticity allows them to slip through bacteriological filters.

Q2. Penicillin leads to inhibition of Mycoplasmas.

1. True

2. False

Ans. Here the correct answer is option ‘b’ false. Mycoplasmas are resistant to even large doses of penicillin because they lack a cell wall; nevertheless, antibiotics that influence protein synthesis, such as tetracyclines or chloramphenicol, can inhibit them.

Q3. Mycoplasmas are cultivated in vitro on nonliving media as 

1. facultative anaerobes

2. obligate aerobes

3. facultative aerobes

4. microaerophiles

Ans. Here the correct answer is option ‘a’ facultative anaerobes. Mycoplasmas can be grown in vitro as facultative or obligate anaerobes on nonliving (rich composition) media.

Q4. By means of which of the following the colonies of mycoplasmas in agar plate can be observed 

1. bright-field microscopy

2. high-power microscope

3. phase contrast microscopy

4. low-power microscope

Ans. The correct answer is option ‘d’ low-power microscope. Colonies on agar plates are often small, necessitating examination with a low-power microscope. The colonies are generally immersed in the agar surface and have a fried-egg appearance.

Q5. On the agar plate, what kind of colonies do Mycoplasmas form?

1. colourless

2. fried-egg

3. lawn formation

4. coloured

Ans. The correct answer is option ‘b’ fried-egg. The colonies are generally immersed in the agar surface and have a fried-egg appearance. Typically, the colonies are extremely small.

Q6. Which of the following substances is required for mycoplasma growth?

1. cholesterol

2. carbon

3. nitrogen

4. glucose

Q7. Which of the bacteria in the following family is pathogenic to citrus and other plants?

1. mycoplasmataceae

2. spiroplamataceae 

3. acholeplasmataceae

4. anaplasmataceae

Ans. The correct answer is option ‘b’ acholeplasmataceae. Spiroplasma Tacea microbes are pathogenic to citrus and other plants. Plant fluids and plant surfaces, as well as arthropods that feed on plants, can be used to separate them.

Q8. Lyticum flagellatum is an endosymbiont that is carried by some types of bacteria.

1. protozoa

2. fungi

3. viruses

4. bacteria

Ans. The correct answer is option ‘a’ protozoa. Certain strains of the protozoan Paramecium tetraurelia have the endosymbiont Lyticum flagellatum.

Q9. The role of A.flagellum is to synthesise

1. vitamins

2. organic acids

3. hormones

4. folic acid and toxins

Ans. Here the correct answer is option ‘d’ folic acid and toxins. One of L.flagellatum’s functions is to create folic acid for its host, and another is to make a toxin that is released into the culture medium.

Q10. Mycoplasmas, unlike L-phase variations, cannot produce a walled bacterial form

1. True

2. False

Ans. The correct answer is option ‘a’ true. Mycoplasmas do not produce walled forms, but L-phase variations are produced from walled bacteria and can usually revert to the regular walled bacterial form.

Q11. Bacteria are commonly considered as plants because

1. Produce spores

2. Cannot move

3. Have cell walls

4. Produce enzyme

Ans. The correct answer is option ‘c’ to have cell walls. The peptidoglycan in bacteria’s cell walls is a repeating structure of long glycan chains with alternate N-acetyl glucosamine and N-acetyl muramic acid; these glycan chains are cross-linked by short peptide fragments to form a strong but flexible support framework. Plants, too, are distinguished by the existence of a cellulose cell wall outside their cell membrane.

Q12. Which among the following is the best source of bacteria ?

1. Water

2. Human body

3. Air

4. Soil

Ans. The correct answer here is option ‘d’ soil. Soil microbes play a key role in nutrient recycling, particularly carbon, nitrogen, phosphorus, and sulphur. Bacteria are a type of microbe that helps to maintain soils health and productivity.

Q13. What age group has the highest prevalence of Mycoplasma pneumoniae infections?

1. 5 to 20

2. 5 to 45

3. 15 to 60

4. 10 to 50

Ans. The correct answer is option ‘a’ 5 to 20. Mycoplasma pneumoniae has been linked to pneumonia in children aged 5 to 9, adolescents, and young adults for a long time. Infection is more common among college students and military recruits, who are more prone to live in close proximity.

Q14. Mycoplasma is

1. eukaryotic and unicellular

2. prokaryotic and multicellular

3. prokaryotic and unicellular

4. eukaryotic and multicellular

Ans. The correct answer is option ‘c’ prokaryotic and unicellular. Prokaryotic organisms with no cell walls are known as mycoplasmas.

Q15. Penicillin and vancomycin have no effect on mycoplasma as

1. there is no Golgi body

2. there is no cell wall

3. there is no nucleus

4. there are no mitochondria

 Ans. The correct answer is option ‘b’ i.e. there is no cell wall. 

Q16. Legume “witches broom” is caused by 

1. fungus

2. bacterium

3. virus

4. mycoplasma

Ans. The correct answer is option ‘d’ mycoplasma. Stress or Mycoplasma cause witch-broom disease, which is a plant disease. The structure of the plant is altered as a result of a malformation. There is a thick mass of shoots emanating from a single spot in this. As a result, the structure resembles that of a broom.