Tag: option b: biotechnology and bioinformatics

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Questions Related to option b: biotechnology and bioinformatics

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

The periplasmic space of the Gram$(-)$ bacteria consists of

  1. Lipoprotein

  2. Mucopeptide

  3. Chromoprotein

  4. Glycoprotein
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Both Gram negative and Gram positive bacteria have a peptidoglycan layer in the cell wall. The peptidoglycan in Gram negative bacteria is present in the periplasmic space. Apart from this, Gram negative bacteria have an outer wall made up of lipopolysaccharide. Peptidoglycan is also called as mucopeptide. It is a polymer that is made up of sugars and amino acids. 

Thus, the correct answer is 'Mucopeptide.'

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

In the Gram staining procedure, all the bacterial cells get stained with

  1. Mercuric chloride

  2. Crystal violet

  3. Malachite green

  4. Saffranin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram staining procedure is based on the principle of the ability of microorganisms to retain color of the stains used during the gram staining process. Gram-positive bacteria retain purple color after staining with crystal violet stain. They are not decolorized by treatment with alcohol. Gram-negative bacteria also get stained with crystal violet stain. However, they are decolorized by the alcohol and lose purple color. When again stained with the second stain safranin, they retain pink color. This major difference is due to the difference in the cell wall component of both the bacteria. 

Thus, the correct answer is 'Crystal violet.'

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

Mucopeptide is abundant in the cell wall of

  1. Cyanobacteria
  2. Gram $(+)$ bacteria
  3. Gram $(-)$ bacteria

  4. Bacteriophage
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Both Gram negative and Gram positive bacteria have a peptidoglycan layer in the cell wall. It is also called as mucopeptide or murein. However, Gram positive bacteria have thick layer of peptidoglycan. Hence, mucopeptide is abundant in the cell wall of gram positive bacteria. Gram negative bacteria have thin layer of mucopeptide. Apart from this, Gram negative bacteria have outer wall made up of lipopolysaccharide. 

Thus, the correct answer is 'Gram (+) bacteria.'

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

What is correct about Escherichia coli and Rhizobium japonicum?

  1. E.coli is Gram - and R. japonicum Gram +

  2. Both Gram +

  3. Both Gram -

  4. E.coli Gram + and R. japonicum Gram -
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both Escherichia coli and Rhizobium japonicum are Gram-negative bacteria, meaning they have a thin peptidoglycan layer and an outer membrane.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane
What is the percentage of mucopolypeptide in the cell wall of Gram (+) bacterium?
  1. $60-70\%$
  2. $70-80\%$
  3. $80-90\%$
  4. $90-100\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls. However, its percentage is higher in cell wall of gram positive bacteria than in cell wall of gram negative bacteria. 

So, B is the correct answer. 

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

Gram negative bacteria detect and respond to chemicals through the receptors in

  1. Muramic acid

  2. Lipopolysaccharide

  3. Porins

  4. Volutin granules
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It holds receptor molecules that help bacteria detect and respond to chemicals in their surroundings

So, the correct answer is 'lipopolysaccharides'

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

Which is not a characteristic of Gram $(+)$ bacteria?

  1. Smooth cell wall

  2. Outer membrane

  3. Prominent mesosomes

  4. Two rings in basal body of flagellum
  5. $70-80\%$ murein in cell wall
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram positive bacteria differs from Gram negative bacteria in having multiple layers of peptidoglycan. They have 20–30 nm thick and smooth cell wall. They contain 70-80% murein or peptidoglycan in cell wall. They do not have outer membrane like Gram negative bacteria, which have an outer LPS layer. Due to absence of outer LPS layer, Gram positive bacteria has two rings in basal body of flagellum, one attached to the plasma membrane and one attached to the peptidoglycan wall. They have prominent mesosomes. Mesosomes are folded invaginations of the plasma membrane.

Thus, the correct answer is 'Outer membrane.'

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

Which one occurs in the cell walls of Gram (+) bacteria only?

  1. Peptidoglycan

  2. Lipopolysaccharide

  3. Teichoic acid

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Teichoic acids are found within the cell wall of most Gram-positive bacteria such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium, and Listeria, and appear to extend to the surface of the peptidoglycan layer.

So, C is the correct option. 

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

Identify the Gram $(-)$ bacterium

  1. Streptomyces coelicolor

  2. Escherichia coli

  3. Ampycolatopsis orientalis

  4. Bacillus subtilis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram-negative bacteria are bacteria that do not retain the crystal violet stain during gram-staining procedure. Gram positive bacteria are bacteria that retain the crystal violet stain during gram staining procedure. Examples of Gram negative bacteria include Escherichia coli, Helicobacter pylori. Examples of Gram positive bacteria include Bacillus subtilis, Streptomyces coelicolor, Streptomyces orientalis (Ampycolatopsis orientalis).

Thus, the correct answer is 'Escherichia coli.'

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

Glycocalyx is

  1. Glycoproteins and glycolipids

  2. Oligosaccharide part of glycolipids and glycoproteins

  3. Lipid and protein parts of glycolipids and glycoproteins

  4. Mucopolysaccharides attached to cell wall.
Reveal answer Fill a bubble to check yourself
B Correct answer
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 'Oligosaccharide part of glycolipids and glycoproteins'.