Tag: option b: biotechnology and bioinformatics

Questions Related to option b: biotechnology and bioinformatics

Production of ethanol $(C _2H _5OH)$ occurs in one of the life processes of

microbiology: organisms in industry option b: biotechnology and bioinformatics biology

  1. Bread mould

  2. Yeast

  3. Mushroom

  4. Penicillium

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Correct Option: B
Explanation:

Ethanol is produced during Anaerobic respiration by yeast, the process commonly known as Fermentation.

Glucose $ \rightarrow\ $ethanol + Carbon dioxide + energy
It is utilised in the breweries and bakeries.
Hence, the correct answer is 'Yeast'.

Christian Gram belongs to which country?

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

  1. Italy

  2. Sweden

  3. Denmark

  4. Germany

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Correct Option: C
Explanation:

Hans Christian Joachim Gram was a Danish bacteriologist noted for his development of the Gram stain.

Peptidoglycan forms many layers in the wall of

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

  1. Gram $(+)$ bacteria

  2. Gram $(-)$ bacteria

  3. Gram neutral bacteria

  4. All the above

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Correct Option: A
Explanation:

On the basis of composition of cell wall, the bacteria are classified into two groups, namely Gram positive and Gram negative bacteria. Cell wall of all bacteria is made up of peptidoglycan. The gram positive bacteria contains many layers of peptidoglycan. However, Gram negative bacteria contains single layer of peptidoglycan. Apart from this, it also contains an outer layer of lipopolysaccharide (LPS). 

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

Arrange the following steps in a correct sequence as per Gram's staining technique:
Treatment with 0.5% iodine solution (1), washing with water. (2) treatment with absolute alcohol/acetone (3), staining with weak alkaline solution of crystal violet (4)

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

  1. 4 $\rightarrow$1 $\rightarrow$2 $\rightarrow$3

  2. 3 $\rightarrow$2 $\rightarrow$1 $\rightarrow$4

  3. 3 $\rightarrow$1 $\rightarrow$2 $\rightarrow$4

  4. 4 $\rightarrow$2 $\rightarrow$3 $\rightarrow$1

Show answer
Correct Option: A
Explanation:

Bacteria can be classified into two groups based upon reaction bacteria to Gram's stain (Christian Gram, 1884. Bacteria are first stained with weakly alkaline solution of crystal violet and then treated with 0.5% iodine solution. This is followed by washing with water and then with alcohol or acetone. Bacteria which retain blue or purple colour are known as Gram (+) bacteria (e.g Bacillus subtilis). Bacteria which do not retain stain and become colourless are called Gram (-) bacteria (e.g. Escherichia coli). Washing of the stain in Gram (- ve) bacteria is due to high lipid content of their cell wall which gets dissolved in organic solvents like acetone. So, the correct answer is '4 →1 →2 →3'.

Which of the given statements are correct?
(i) Bacillus subtilis is a Gram(+) bacteria
(ii) Escherichia coli is a Gram (-) bacteria
(iii) Washing of the Gram's stain in Gram (-) bacteria is due to high lipid content of the cell wall, which gets dissolved in organic solvents like acetone

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

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (i) and (iii)

  4. (i), (ii) and (iii)

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Correct Option: D
Explanation:

Bacteria can be classified into two groups based upon reaction bacteria to Gram's stain (Christian Gram, 1884. Bacteria are first stained with weakly alkaline solution of crystal violet and then treated with 0.5% iodine solution. This is followed by washing with water and then with alcohol or acetone. Bacteria which retain blue or purple colour are known as Gram (+) bacteria (e.g Bacillus subtilis). Bacteria which do not retain stain and become colourless are called Gram (-) bacteria (e.g. Escherichia coli). Washing of the stain in Gram (- ve) bacteria is due to high lipid content of their cell wall which gets dissolved in organic solvents like acetone. So, the correct answer is '(i), (ii) and (iii)'.

Which of the following stain/s is used by Hans Christian Gram to classify bacteria as gram negative and gram positive bacteria?

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

  1. Carbolfuchsin

  2. Saffronin

  3. Crystal violet

  4. All of the above

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Correct Option: D
Explanation:

Hans Christian Gram used carbolfuchsin, safranin, and crystal violet to classify bacteria as gram positive and gram negative.

So, the correct option 'all of the above'.

During Gram's stain

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

  1. All bacteria whether Gram (+)ve or (-)ve, take crystal violet stain

  2. Only Gram +ve bacteria take crystal violet stain

  3. Only Gram (-)ve bacteria take crystal violet stain

  4. Gram (+)ve bacteria lose this stain after alcohol treatment and take red stain of safranin

Show answer
Correct Option: B
Explanation:

  1. Gram staining distinguishes between the Gram-positive and Gram-negative bacteria on the basis of the composition of the cell wall.
  2. Gram-positive bacteria have a thick layer of peptidoglycan which helps to retain stain.
  3. The Gram-positive bacteria is first treated with Gram stain which is retained by them. After staining they are treated with alcohol to decolourize. 
  4.  Decolorizing the cell causes this thick cell wall to dehydrate and shrink, which closes the pores in the cell wall and prevents the stain from exiting the cell. 
  5. When they are stained by saffranine, they are unable to take the stain and appears blue. 
  6. Gram staining bacteria take up the Gram stain but they are unable to retain them due to the thin layer of peptidoglycan.
  7. When they are exposed to alcohol, decolourizer dissolves the lipids in the cell walls, which allows the crystal violet-iodine complex to leach out of the cells.
  8. When stained with safranin, they take the stain and appears red in colour.
So, the correct answer is 'Only Gram +ve bacteria take crystal violet stain'.

Which of the following is not the layer of chemically complex cell envelope of prokaryotic cells?

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

  1. Glycocalyx

  2. Chromatophore

  3. Cell wall

  4. Cell membrane

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Correct Option: B
Explanation:
Chromatophores are the pigment-containing and light-reflecting cell. They have no contribution to the protection and structure of the cells. Thus, they are not present in the chemically complex cell envelop of prokaryotic organisms.
Glycocalyx surrounds the cell membrane of bacteria. It is a glycoprotein and glycolipid layer.
Cell wall is the outer most layer of the plant cell. It is composed of cellulose.
Cell membrane is made up of lipids and proteins.
So, the correct answer is 'Chromatophore'.

In which of the following bacteria, cell membrane invaginates and gets folded inside the cell forming mesosomes?

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

  1. Salmonella

  2. Pseudomonas

  3. Rhizobium

  4. Bacillus

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Correct Option: D
Explanation:

Cell membrane invaginates and gets folded inside the cell forming mesosomes in bacillus because mesosomes are present only in the gram-positive organisms. All the other bacteria are gram-negative organism.

So, the correct answer is 'Bacillus'.

Cell wall is chemically made up of peptidoglycan and lipopolysaccharides in

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

  1. Gram Positive bacteria

  2. Protists

  3. Mycoplasma

  4. Gram Negative bacteria

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Correct Option: D
Explanation:

Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. They are an important medical challenge, as their outer membrane protects them from many antibiotics (including penicillin); detergents that would normally damage the peptidoglycans of the (inner) cell membrane; and lysozyme, an antimicrobial enzyme produced by animals that form part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopolysaccharide (LPS) whose lipid A component can cause a toxic reaction when these bacteria are lysed by immune cells. 

So, the correct answer is D.