The component of bacteria that retains the crystal violet stain d

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 Multiple Choice QuestionsMultiple Choice Questions

111.

Select the correct statement regarding reproduction

  • Mating in dogs is synchronised with lunar cycle.

  • Salamanders always have internal fertilisation.

  • In Trygon, the male introduces sperms into female through a modified pelvic fin.

  • Catla has internal fertilisation


112.

Which form of reproduction is correctly matched?

  • Euglena transverse binary fission

  • Paramecium longitudinal binary fission

  • Amoeba multiple fission

  • Plasmodium binary fission


113.

Assertion: Many plants are propagated vegetatively even though they bear seeds.

Reason: Potatoes multiply by tubers and apple by cutting.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


114.

Noncleidoic eggs occur in

  • birds

  • fish

  • reptiles

  • platypus


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115.

Division in a bacterial cell is carried out through

  • multiple fission

  • binary fission

  • budding

  • plasmotomy


116.

Which of the following two hormones are essential for induced breeding of fishes?

  • TSH and ACTH

  • Oestrogen and progesterone

  • FSH and LH

  • Vasopressin and oxytocin


117.

One micrometer is equal to

  • 0.0001 mm

  • 0.001 mm

  • 0.01 mm

  • 0.00001 mm


118.

Product of sexual reproduction generally generates

  • longer viability of seeds

  • prolonged dormancy

  • new genetic combination leading to variation

  • large biomass


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119.

Which of the following processes was discovered by Lederberg and Tatum (1946)?

  • Transduction

  • Transformation

  • Asexual reproduction

  • Conjugation


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120.

The component of bacteria that retains the crystal violet stain during Gram staining is

  • O- antigen

  • lipopolysaccharide

  • peptidoglycan

  • cytoplasmic membrane


C.

peptidoglycan

Gram staining is the method of differentiating bacterial species into two large groups, i.e., Gram positive and Gram negative bacteria based on the physical properties of their cell walls.

In the process of Gram staining 

- alcohol is used for decolourlisation process. It solubilises lipid but does not solubilise peptidoglycan layer.

As Gram positive bacteria has less lipid percentage as compared to peptidoglycan. Thus, peptidoglycan which does not get solubilised retain the Gram stain and Gram negative bacteria which has thinner peptidoglycan layer cannot retain the Gram stain.


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