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

Which one of the following is absent in eukaryotes?

  1. Nucleolus

  2. Plastid

  3. Mesosome

  4. Ribosomes
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
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

DNA of Escherichia coli is

  1. dsDNA and circular

  2. dsDNA and linear

  3. ssDNA and linear

  4. ssDNA and circular.
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Mitochondria are absent in

  1. Bacteria

  2. Red Algae

  3. Green Algae

  4. Brown Algae.
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
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

Bacteria with tuft of flagella at one pole are

  1. Amphitrichous

  2. Peritrichous

  3. Atrichous

  4. Lophotrichous
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.

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

Bacteria having a tuft of flagella at both the poles are

  1. Atrichous

  2. Peritrichous

  3. Lophotrichous

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

Amphitrichous bacteria possess a single flagellum or a tuft of flagella at both poles of the cell. This distinguishes them from peritrichous (all over) or lophotrichous (tuft at one end) arrangements.

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
Correct sequence of layer of bacterial cell envelope from outward to inward is
  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.

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

Which cell organelle is absent in anaerobic bacteria?

  1. Mitochondria

  2. Golgi body

  3. E.R.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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.