Tag: the world of microbes

Quizzes (12) Questions (108)

Questions Related to the world of microbes

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Some bacteria are considered plants as they

  1. Are green in colour

  2. Have rigid cell wall

  3. Have chlorophyll

  4. Have stomata
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Some bacteria, such as cyanobacteria, are photosynthetic and contain chlorophyll, which led to their historical classification as plants.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

In bacteria the site for respiratory activity is found in

  1. Episome

  2. Microsome

  3. Ribosome
  4. Cell membrane$/$ Mesosome
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In bacteria the site for respiratory activity is found in mesosomes. Mesosomes are folded invaginations in the cell membrane of bacteria. They increases the surface area required for respiration. They contain respiratory enzymes. It is the site of respiratory activity.

Thus, the correct answer is 'Cell membrane/ Mesosome.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Sex factor of bacteria is

  1. RNA

  2. Sex pili

  3. F-factor

  4. Chromosome replicon
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

F-factor is also called as fertility factor. It is the sex factor of bacteria. It allows the transfers of genes from one bacterium carrying the factor to another bacterium lacking the factor by the process of conjugation. It is found in some bacteria only.

Thus, the correct answer is 'F-factor.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Murein of bacterial cell wall is derivative of

  1. Vitamin

  2. Fat

  3. Organic acid

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

The bacterial cell wall is made up of Peptidoglycan or murein. It is a polymer that is made up of sugars and amino acids. The sugar component is made up of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). NAM is then attached to an amino acid chain of L-alanine, D-glutamic acid, diaminopimelic acid (DAP) and D-alanine. 

Thus, the correct answer is 'Sugar.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Bacterial cell membrane is made up of

  1. Chitin

  2. Cellulose

  3. Proteins and phospholipids

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

Bacteria is a unicellular prokaryotic organism. It has a cell wall around the cell membrane. The bacterial cell membrane is made up of proteins and phospholipids. the proteins in are randomly distributed in the phospholipid bilayer of the cell membrane.

Thus, the correct answer is 'Proteins and phospholipids.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Teichoic acid is present in cell wall of

  1. Bacteriophage

  2. Mycoplasma

  3. Nostoc

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

Teichoic acids are characteristic components of the cell wall of Gram-positive bacteria. Pneumococcus is a well-known Gram-positive bacterium, whereas the others listed do not possess this specific cell wall structure.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Some bacteria have a capsule outside cell wall. It is made of

  1. Protein

  2. Cellulose

  3. Fat

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

Some bacteria have a capsule outside cell wall. It is made up of mucopolysaccharide. The functions of mucopolysaccharide are;

  • It enhances the ability of bacteria to cause disease. 
  • It protects cells from engulfment by macrophages. 
  • It protects cells from desiccation.
Thus, the correct answer is 'Mucopolysaccharide.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Why is a capsule advantageous to a bacterium?

  1. It provides means of locomotion

  2. It allows bacteria to "hide" from host's immune system

  3. It allows the bacterium to attach to surface

  4. It protects the bacterium from desiccation.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Bacterial capsule usually consists of a polysaccharide layer that lies outside the cell envelope. The capsule is found in both gram-positive and gram-negative bacterium.
  • The capsule is considered as virulence factor because it enhances the ability of bacteria to cause disease. It protects the bacterial cell from engulfment by macrophages.
  • Capsules also contain water which protects the bacterium from desiccation.
So, the correct answer is 'It protects the bacterium from desiccation'.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Select the wrong statement of a bacterial cell

  1. Mesosome is formed by extensions of plasma membrane into cell

  2. Pili are elongated tubular structures made up of a protein

  3. Flagellum is composed of filament, hook and basal body

  4. Ribosomes are about 30 nm by 50 nm in size

  5. Fimbriae are small bristle like fibres sprouting out of cell.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bacterial ribosomes are 70S, consisting of 30S and 50S subunits. The statement claiming they are 30 nm by 50 nm is incorrect as these numbers refer to the Svedberg units of the subunits, not the physical dimensions in nanometers.