Tag: option b: biotechnology and bioinformatics

Questions Related to option b: biotechnology and bioinformatics

Bacteria were grown in a medium containing heavy isotope of nitrogen (N15) for many generations and all their DNA contained many heavy nitrogen only. A bacterium of this type was transferred to normal medium and allowed to duplicate. After two divisions of heavy DNA is likely to be that

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Only one daughter cell will have heavy DNA

  2. Two daughter cells have normal DNA and other two

  3. All daughter cells have heavy DNA

  4. Half daughter cells have heavy DNA and other half have normal DNA

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Correct Option: B
Explanation:

After two divisions, four bacterial cells are formed in which two daughter bacterial cells have normal DNA and other two have both normal and heavy DNA because DNA replicates by semiconservative method in bacteria.

The term glycocalyx is used for

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Cell wall of bacteria

  2. Bacterial cell glyco-engineered to possess N-glycosylated proteins

  3. A layer surrounding cell wall of bacteria

  4. A layer present between cell wall and cell membrane of bacteria

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Correct Option: D
Explanation:
  • Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  • It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  • So, the correct answer is 'A layer present between cell wall and membrane of bacteria'.

Teichoic acid is present in which component of bacteria

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Cell wall

  2. Plasma membrane

  3. Outer membrane

  4. Flagella.

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Correct Option: A
Explanation:
  • The peptidoglycan layer in Gram-positive bacteria is made up of with anionic glycopolymers called wall teichoic acids.
  •  It plays an important role in determining the cell shape, regulation of cell division etc.
  • Teichoic acids are found within the cell wall of Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium etc.
  • So, the correct answer is 'Cell wall'.

How many layers are there in the cell envelope of Gram (-) ve bacteria?

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. 2

  2. 3

  3. 4

  4. 6

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Correct Option: B

Gram staining procedure of bacteria is based upon the properties of

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Cell membrane

  2. Cell wall

  3. Capsule

  4. DNA.

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Correct Option: B

Choose the correct answers from the alternatives given.
Eubacterial cell walls are composed of ........., and a sticky mesh of polysaccharides, a ......... often surrounds the wall

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. peptidoglycan, plasma membrane

  2. cellulose; glycocalyx

  3. cellulose; plasma membrane

  4. peptidoglycan; glycocalyx

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Correct Option: D
Explanation:

Eubacterial cell walls are composed of peptidoglycan and a sticky mesh of polysaccharides, a glycocalyx often surrounds the wall.

So, the correct option is 'peptidoglycan; glycocalyx'.

Some gram $-$ve bacteria have peptidoglycan and an extra layer of.

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Lipo polysaccharide

  2. Lipo-protein

  3. Protein

  4. Both A and C

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Correct Option: A
Explanation:
Both Gram negative and Gram positive bacteria have a peptidoglycan layer in the cell wall. Peptidoglycan is also called as mucopeptide. It is a polymer that is made up of sugars and amino acids. Gram positive bacteria have thick layer of peptidoglycan. However, Gram negative bacteria have thin layer of peptidoglycan. Apart from this, Gram negative bacteria have outer wall made up of lipopolysaccharide.
Thus, the correct answer is 'Lipo polysaccharide.'

Choose the correct answers from the alternatives given.
In comparison to Gram -ve bacteria, Gram +ve bacteria

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. have less peptidoglycan

  2. have more complex cell walls

  3. retain the crystal violet dye

  4. are more resistant to antibiotics

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Correct Option: C
Explanation:

Gram-positive bacteria are stained dark blue or violet by Gram staining. This is in contrast to gram-negative bacteria, which take up the counterstain and appear red or pink. 

So, the correct option is 'retain the crystal violet dye'.

State whether the following statements are true or false.
When treated with crystal violet and subsequently with iodine some bacteria remain colourless and these are called gram +ve bacteria.

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. True

  2. False

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Correct Option: A
Explanation:

When treated with crystal violet and subsequently with iodine, some bacteria remain colorless and these are called gram +ve bacteria.

So, the correct option is 'True'.

State whether the following statements are true or false.
Gram stain which is extracted from gram pods is used to differentiate Gram -ve and Gram +ve bacteria.

botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

  1. True

  2. False

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Correct Option: A
Explanation:

Gram stain is the most important staining procedure. Gram-positive bacteria stain purple, whereas gram-negative bacteria stain pink. 

So, the correct option is 'True'.