Tag: microbiology: organisms in industry

Questions Related to microbiology: organisms in industry

Glycocalyx is responsible for__________________.

  1. Antigens like those of blood groups ABO

  2. Immune reactions and histocompatibility

  3. Hormone receptors

  4. All the above.


Correct Option: D

How many basal body rings are present in gram (+)ve bacterial cells

  1. $3$

  2. $2$

  3. $4$

  4. $5$


Correct Option: B
Explanation:

Gram-positive organisms have two of these basal body rings, one in the peptidoglycan layer and one in the plasma membrane.

Prokaryotic and eukaryotic flagella differ in

  1. Type of movement and placement

  2. Location and mode of functioning

  3. Microtubular structure and function

  4. Microtubular organisation and type of movement


Correct Option: D
Explanation:
 PROKARYOTIC FLAGELLA  EUKARYOTIC FLAGELLA 
 1) It is made up of flagellin proteins.2) It is smaller in size and is narrower.3) It is designed to perform clockwise and anti-clockwise movements.4) They do not contain microtubule-based structures. 1) It is made up of tubulin proteins.2) It is larger in size and is thicker.3) It is designed to perform back and forth movements. 4) They are made up of microtubules.

So, the correct answer is 'Microtubular organisation and type of movement'.

Choose the wrong statements regarding bacterial cell
(a) Glycocalyx is the outer most envelope in bacteria
(b) Gycocalyx could be a loose sheath called capsule
(c) Glycocalyx may be thick and tough called slime layer.
(d) A special structure formed by the plasma membrane is called mesosome.
(e) Small bristle-like fibres sprouting out of the cell are called fimbriae.

  1. a and c are wrong

  2. a and b are wrong

  3. b and c are wrong

  4. a and d are wrong

  5. c and d are wrong.


Correct Option: C

Glycocalyx is associated with

  1. Plasmalemma

  2. Nucleus

  3. Nucleolus

  4. Nucleosome


Correct Option: A
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 'Plasmalemma'.

Slime layer and capsule in bacteria are modifications of

  1. Glycocalyx

  2. Cell wall

  3. Plasma membrane

  4. Pellicle

  5. Tonoplast.


Correct Option: A

Teichoic acid occurs is the wall of

  1. Gram -ve bacteria

  2. Gram +ve bacteria

  3. Mycoplasma

  4. Cyanobacteria.


Correct Option: B

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

  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


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

  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


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

  1. Cell wall

  2. Plasma membrane

  3. Outer membrane

  4. Flagella.


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'.