Tag: the world of microbes

Questions Related to the world of microbes

Which one of the following is absent in eukaryotes?

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

  1. Nucleolus

  2. Plastid

  3. Mesosome

  4. Ribosomes

Show answer
Correct Option: C
Explanation:
  • Mesosomes are absent in eukaryotes.
  • Mesosomes refers to the folded invaginations in the plasma membrane of prokaryotes or bacterial cells.
  • Its main function is to increase the surface area of the plasma membrane. 
  • When the surface area of the membrane is increased it helps to carry out the cellular respiration more efficiently.
  • So, the correct answer is 'Mesosome'.

DNA of Escherichia coli is

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

  1. dsDNA and circular

  2. dsDNA and linear

  3. ssDNA and linear

  4. ssDNA and circular.

Show answer
Correct Option: A
Explanation:

Escherichia coli is a Gram-negative, facultatively anaerobic bacteria. It is found in the intestine of warm-blooded organisms. It has one circular chromosome. The chromosome contains double-stranded DNA. It may contain some circular plasmids as well as extrachromosomal material.

Thus, the correct answer is option A.

Mitochondria are absent in

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

  1. Bacteria

  2. Red Algae

  3. Green Algae

  4. Brown Algae.

Show answer
Correct Option: A
Explanation:
  • Mitochondria are absent in bacteria and blue-green algae.
  • A prokaryotic cell lacks membrane-bound cell organelles and nucleus whereas, a eukaryotic cell consists of membrane-bound cellular organelles and well-defined nucleus.
  • Red algae, green algae and brown algae have eukaryotic cells (well-defined nucleus and cellular organelles).
  • So, the correct answer is 'Bacteria'.

Bacteria with tuft of flagella at one pole are

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

  1. Amphitrichous

  2. Peritrichous

  3. Atrichous

  4. Lophotrichous

Show answer
Correct Option: D
Explanation:

A. Amphitrichous bacteria have flagella (single or multiple) extending from both ends of the cell.

B. Peritrichous bacteria have flagella projecting in all directions around the cell.
C. Atrichous bacteria lack flagella. 
D. Lophotrichous bacteria have a tuft of flagella located at the same point on the bacterial cell.
So, the correct answer is 'Lophotrichous'.

Bacteria having a tuft of flagella at both the poles are

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

  1. Atrichous

  2. Peritrichous

  3. Lophotrichous

  4. Amphitrichous.

Show answer
Correct Option: D

A bacterial cell contains.

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

  1. Mesosome, Golgi bodies and nucleoid

  2. Mesosome and Golgi bodies

  3. Mesosome and nucleoid

  4. Golgi bodies and nucleoid

Show answer
Correct Option: A
Correct sequence of layer of bacterial cell envelope from outward to inward is
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

  1. Cell wall $\rightarrow$ Glycocalyx $\rightarrow$Cell membrane

  2. Cell membrane $\rightarrow$ Glycocalyx $\rightarrow$ Cell wall

  3. Glycocalyx $\rightarrow$ Cell wall $\rightarrow$ Cell membrane

  4. Glycocalyx $\rightarrow$ Cell membrane $\rightarrow$ Cell wall

Show answer
Correct Option: C
Explanation:

Glycocalyx is the outermost layer of the cell envelope. Cell wall lies between plasma membrane and glycocalyx.

So, the correct answer is 'Glycocalyx → Cell wall → Cell membrane'.

Which cell organelle is absent in anaerobic bacteria?

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

  1. Mitochondria

  2. Golgi body

  3. E.R.

  4. All of the above

Show answer
Correct Option: D
Explanation:

An anaerobic organism or anaerobic bacteria is any organism that does not require oxygen for growth. It may react negatively or even die if oxygen is present. Mitochondria, Golgi body and ER are organelles of eukaryotic organisms. Since anaerobic bacteria is prokaryotic, they are absent in anaerobic bacteria.