Tag: micro organisms

Questions Related to micro organisms

The latest view for the origin of virus is that

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. They arose from nucleic acid and protein found in primitive water.

  2. They arose from bacteria as a result of loss of cell wall.

  3. They arose from some of the bacteria, which had developed a nucleus only.

  4. They are modified plasmids, which are fragments of the nucleic acids of the host.

Show answer
Correct Option: D
Explanation:

Viruses play an important role in horizontal gene transfer and genetic diversity. The evolution history showcases the origin of viruses as to have evolved from plasmids when pieces of DNA moved between cells. As
big bits of cellular DNA became independent and some DNA stuck with cell genomes. Thus, the correct answer is option D.

A virus can be considered living being as it

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Reproduces inside the host

  2. Respires

  3. Can cause disease

  4. Responds to touch stimuli

Show answer
Correct Option: A
Explanation:
  • A virus is an organism that can be considered both living and non-living. 
  • It can be considered as living when it is inside any host (bacterium) as the virus infects the host cell and replicates inside it making several copies of it. 
  • When it is outside the host cell, it is non- living as it can not carry out its life- processes of either reproducing or digestion etc.
  • Thus, option A is correct here.

Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Monera

  2. Protista

  3. Fungi

  4. None of these

Show answer
Correct Option: D
Explanation:

Viruses are non-cellular organisms and replicate only when they infect the host cell. 

Viruses belong to none of these. Option D.

Viruses are living because

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. They can reproduce.

  2. They have protein synthesising machinery.

  3. They have some genes.

  4. They are parasites.

Show answer
Correct Option: A
Explanation:

Reproducing is one of the characteristics of the living organisms. Viruses definitely multiply. Viruses must use host cells to create more virions. Since viruses don’t have organelles, nuclei or even ribosomes, they don’t have the tools they need to copy their genes and create whole new virions. Instead, viruses enter living cells and then hijack the host’s cellular equipment to copy viral genetic information, build new capsids and assemble everything together. So, the correct answer is 'They can reproduce'.

All are oncogenic virus except?

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Influenza virus

  2. Hep. B virus

  3. HIV

  4. V. Zoster

Show answer
Correct Option: D
Explanation:
Oncogenic viruses are those that are suspected of causing cancer in human beings and some other animals. They all have DNA as their genetic material. For example, human papillomaviruses, the Epstein-Barr virus, and the hepatitis B virus, the HIV, and influenza virus. The V. Zoster virus is not an oncogenic virus.

So, the correct answer is 'V. Zoster'.

Which of the following is the characteristic feature that distinguishes an algae from fungi?

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Heterotrophic

  2. Autotrophic

  3. Parasitic

  4. Sporophytic

Show answer
Correct Option: B
Explanation:

The algae posses the chlorophyll pigments in the cells which allow these organisms to prepare the food by the process of photosynthesis. They are autotrophic because they can prepare the food on their own. The fungi are the heterotrophic or saprophytic organisms as they do not possess the chlorophyll pigments. They cannot prepare the food and depend on the other sources for food. 

Thus, the correct answer is option B. 

Which of the following microorganism is autotrophic in nature?

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Algae

  2. Bacteria

  3. Fungi

  4. None of the above

Show answer
Correct Option: A
Explanation:

An organism that is capable of synthesizing its own food from inorganic substances using light or chemical energy is called as autotrophic organism. It includes green plants, algae and certain bacteria. Algae are photoautotrophs meanings they use light as the source of energy to prepare their food.

Thus, the correct answer is option A. 

Algae can grow

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. On the surface of water

  2. Inside the water

  3. On the tree

  4. None of the above

Show answer
Correct Option: A
Explanation:
Both macroalgae and microalgae need sunlight, water,chlorophyll, carbon dioxide, the correct environment and nutrients to grow and make their own energy. Macroalgae have air-bladders or flexible stipes which help the algae to rise to the surface of the water and catch the sunlight.

So, the correct answer is 'A'.

Which of the following statements is true about viruses?

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Viruses are filterable facultative parasites

  2. Viruses are capable of performing metabolic activities on their own

  3. All viruses known to man are facultative parasites

  4. Some viruses have cellular structure and are saprophytes

Show answer
Correct Option: A
Explanation:

Viruses are obligate filterable parasites capable of independent existence and when they enter inside the body of the host they start utilising the host machinery for its own reproduction. 

Thus, the correct answer is option A. 

Make correct pair

A. Cyanophyceae                      b. Green colour
B. Chlorophyceae                     a. Blue green colour
C. Phaeophyceae                      d. Red colour
D. Rhodophyceae                     c. Brown colour

biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

  1. Aa, Bb, Cc, Dd

  2. Ab, Bc, Cd, Da

  3. Ab, Ba, Cd, Dc

  4. Ad, Bd, Ca, Db

Show answer
Correct Option: A
Explanation:
(A) Cyanophyceae - the blue green color is because of pigments phycobilins and phycocyanin, in addition to chlorophyll pigments
(B) Chlorophyceae  -The green colour is due to presence of a chl -a chl - b xanthophylls and carotenes 
(C) Phaeophyceae _ Brown colour is due to presence of pigment  fucoxanthin in addition to chlorophyll pigments
(D) Rhodophyceae _ Colour is red due to presence of r - pigment (r_phycoerythin) in addition to chlorophyll pigments
So, the correct answer is 'Aa, Bb, Cc, Dd'