Tag: gram staining

Quizzes (0) Questions (77)

Questions Related to gram staining

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

Gram positive bacteria are more rigid than Gram negative bacteria because of the 

  1. presence of multiple layers of peptidoglycan

  2. lack of D-amino acids in their cell wall

  3. presence of N-acetylgalactosamine in the peptidoglycan backbone

  4. presence of lipopolysaccharide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Because gram-positive bacteria are surrounded by layers of peptidoglycan which is many times thicker than is found in the gram negatives. Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which is surrounded by an outer membrane containing lipopolysaccharide which is not present in gram-positive bacteria.

So, the correct answer is 'presence of multiple layers of peptidoglycan'.
Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Mesosomes were taken as

  1. Golgi bodies

  2. Plastids

  3. Mitochondria

  4. Endoplasmic recticulum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the vesicle of mesosomes, the respiratory enzymes and the components of electron transport such as ATPase, dehydrogenase, cytochrome are present in low amount. So, they were considered anologous to mitochondria for their respiratory function. 

So, the correct option is 'Mitochondria'.

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

Which of the following statements is false?

  1. Bacteria glycocalyx differ in composition and thickness among diffrent bacteria.

  2. Bacterial envelope has a layered structure and each layer has a distinct function but they act as a single structure

  3. Bacteria are organelle less and contains ribosomes

  4. Number and arrangements of flagella is variable in bacteria.
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

____________ is a microbial bio-control agent.

  1. Pseudomonas

  2. Penicillium

  3. Bacillus thuringiensis

  4. Clostridium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pseudomonas are aerobic, gram-negative bacteria, ubiquitous in agricultural soils, and are well adapted to growing in the rhizosphere. Pseudomonads possess many traits that make them well suited as biocontrol and growth-promoting agents. 

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

Teichoic acid is present in 

  1. Gram +ve bacteria

  2. Gram -ve bacteria

  3. Spirochaete

  4. Actinomycetes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Teichoic acids are found within the cell wall of Gram-positive bacteria. The main function of teichoic acid is to provide rigidity to the cell wall by attracting cations, such as magnesium and sodium.

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

Which one of the following dyes cannot be used for staining chromatin material?

  1. Acetocarmine

  2. Crystal violet

  3. Haematoxylin

  4. Schiff's reagent (Feulgen stain)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Crystal violet dye is used as a histological stain and in Gram's method of classifying bacteria.
Rest all other dyes in option as acetocarmine, haematoxylin and Schiff's reagent are used to stain chromosome.
Thus, the correct answer is option B.

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

All the following statements are true about exotoxins except 

  1. They are protein in nature.

  2. Are heat labile.

  3. Produced by Gram + positive bacteria.

  4. Are highly antigenic.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. Exotoxin is secreted during lysis of the cell. 

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

The main difference between Gram +ve and Gram -ve resides in the composition of 

  1. Cilia

  2. Cell wall

  3. Cell membrane

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

The Gram-negative cell wall is characterized by presence of outer membrane, a thinner peptidoglycan layer and extensive periplasmic space surrounding the peptidoglycan. The uppermost layer of the outer membrane has lipopolysaccharide, while the innermost layer is a typical lipid layer. Presence of membrane channels formed by porin proteins in outer membrane impart make them less penetrable as compared to Gram positive cells. Gram positive cells are characterized by presence of single thick layer of cell wall which is made up of peptidogycan, teichoic acid and lipoteichoic acid. They lack outer membrane and porin and have narrow periplasmic space. Plasma membrane is the unit membrane in both, Gram positive and Gram negative bacteria, present beneath cell wall with primarily phospholipids (making up about 30–40% of the membrane mass) and proteins (60–70%). The dense gelatinous solution surrounded by plasma membrane is cytoplasm which has same composition in both, Gram positive and Gram negative cells. Cilia are the eukaryotic structures which are absent in bacteria as they are prokaryotic. 

Thus, the correct answer is option B.

Multiple choice botany cell and cell organelles gram staining microbiology: organisms in industry cell wall and cell membrane

A prokaryotic cell lacks 

  1. Cell wall

  2. Cell membrane

  3. Cytoplasm

  4. Nucleolus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A prokaryotic cell lacks a nucleolus. A prokaryote is a single-celled organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelles. All the intracellular water-soluble components are located together in the same volume enclosed by the cell membrane, rather than in separate cellular compartments.