Tag: biology

Questions Related to biology

The first eukaryotes to evolve were

  1. Bryophytes

  2. Green algae

  3. Blue-green algae

  4. Protistans


Correct Option: D
Explanation:

  • The simple protists were similar to bacteria but they gradually evolved as eukaryotes wherein each cell is having a nucleus. 
  • They are not an animal, plant or fungus but they may be closely related to plants. 
  • They may survive alone or may group as per the convenience.
  • The correct answer is D. 

Which of the following is a symbiont?

  1. Vorticella

  2. Paramecium

  3. Colpidium

  4. Trichonympha


Correct Option: D
Explanation:
  • Zootermopsis, the pine woods termite, contains vast numbers of the wood engulfing symbiont Trichonympha, along with a number of other species, such as the primitive flagellate, Streblomastix and Trichomonas, a genus commonly found in warm, moist interiors of virtual all species of animals. 
  • Trichonympha along with these huge cells are bacteria residing in the termite gut assist in breaking down the cellulose. Hence the correct option is D.

Entamoeba histolytica is

  1. Monogenetic

  2. Digenetic

  3. Free-living

  4. None of the above


Correct Option: A
Explanation:
This kind of protozoan parasite resides in the mucous and sub-mucous layer of the large intestine specially at the iliocaecal junction and cause dysentery, diarrhoea, hepatitis and liver abscess in man. Entamoeba  histolytica is a monogenetic parasite as its entire life history is completed in a single host.
So, the correct answer is 'Monogenetic'

Water collecting canals around the contractile vacuole are called _________.

  1. Incurrent canals

  2. Excurrent canals

  3. Radiating canals

  4. None of the above


Correct Option: C
Explanation:

Water collecting canals around the contractile vacuole are called Radiating canals The contractile vacuole is the part that contracts and forces extra water out of the cell. The radiating canals are the paths to the contractile vacuole. In Paramecium, these are two contractile vacuoles while one in Amoeba.

Macronucleus of Paramecium takes part in

  1. Transmission of hereditary characters

  2. Controlling normal cellular metabolism

  3. Production of variations and adaptability

  4. All the above


Correct Option: B
Explanation:
Paramecium has two types of nucleus- micronucleus and macronucleus. Macronucleus perform common cellular functions and micronucleus takes part in sexual reproduction. 
Thus, the correct answer is option (B).

Entamoeba histolytica secretes proteolytic enzyme called _________.

  1. Polypeptidase

  2. Histolysin

  3. Pepsin

  4. Trypsin


Correct Option: B
Explanation:

Entamoeba histolytica secretes proteolytic enzyme called Histolysin.

Maximum speed of a protist is

  1. 20 $\mu m/sec$

  2. 2.0 $mm/sec$

  3. 200 $\mu m/sec$

  4. 2 $ cm/sec$


Correct Option: B
Explanation:

  • The movement of protists is affected by various surrounding factors,  certain protists move by special locomotive structures. 
  • Ciliated cells and flagellated cells move faster than others, but the flagellated cells are able to move as fast as 2.0 mm/sec.
  • The correct answer is B.

In Amoeba and Paramecium osmoregulation occurs through

  1. Pseudopodia

  2. Nucleus

  3. Contractile vacuole

  4. General surface


Correct Option: C
Explanation:
Osmoregulation is the maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentration. In Amoeba and paramecium, the osmoregulation occurs through Contractile vacuole. The function of a contractile vacuole in protozoan is to expel out excess water via diffusion.
So, the correct answer is 'Contractile vacuole'.

If all ponds and puddles are destroyed, the organism likely to be destroyed is

  1. Leishmania

  2. Trypanosoma

  3. Ascaris

  4. Plasmodium


Correct Option: D
Explanation:
The breeding places of this mosquito is ponds, marshes, swampy areas etc. So, if all the ponds and puddles are destroyed. Anopheles will not be able to survive leading to destruction of its parasite, Plasmodium.
So, the correct answer is 'Plasmodium'

Protistan genome has

  1. Membrane bound nucleoproteins embedded in cytoplasm

  2. Free nucleic acid aggregates

  3. Gene containing nucleoproteins condensed together in loose mass

  4. Nucleoprotein in direct contact with cell substance


Correct Option: A
Explanation:

Protista are eukaryotic organism. They have well defined membrane bound nucleus, which encloses genetic material and membrane bound cell organelle in cytoplasm.

Therefore the correct option is A.