Tag: zoology

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Questions Related to zoology

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Cyanobacterial cells which are specialized for nitrogen fixation are

  1. Phycobilisomes

  2. Heterocysts

  3. Hormogonia

  4. Trichomes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Anabaena is a cyanobacteria. It has ability to fix atmospheric nitrogen. It converts nitrogen into ammonia. The heterocysts present in it are specialized cyanobacterial cells for nitrogen fixation. It contains enzyme nitrogenase. Nitrogenase is inactivated by oxygen. Hence, the heterocyst creates a micro anaerobic environment.

Thus, the correct answer is 'Heterocysts.'

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.......... are nitrogen fixing, aerobic, photosynthetic and Gram $(-)$ bacteria

  1. Archaebacteria

  2. Cyanobacteria

  3. Chlorobacteria

  4. Rickettsiae
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cyanobacteria are photosynthetic prokaryotes that possess the ability to fix atmospheric nitrogen. They are Gram-negative and contain chlorophyll a, which allows them to perform oxygenic photosynthesis.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

A membranous coiled semicircular structure attached to plasma membrane and found in blue-green algae is called

  1. Lamellasome

  2. Lomasome

  3. Mesosome

  4. Microsome
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A membranous coiled semicircular structure attached to plasma membrane and found in blue-green algae is called as Lamellasome. It is approximately 200 mμ in diameter. Mesosome is folded invagination found in the plasma membrane of bacteria that increases the surface area. They are the site of respiration. Microsome is a fragment of endoplasmic reticulum. It is an artificial structure and is not present in living cell.

Thus, the correct answer is 'Lamellasome.'

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Blue colour of blue-green algae is due to

  1. Phycocyanin and allophycocynanin

  2. Phycoerythrin

  3. Anthocyanin

  4. Anthoxanthin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blue-green algae are also called as cyanobacteria. The blue colour of blue-green algae is due to presence of pigments phycocyanin and allophycocyanin. The green colour is due to presence of chlorophyll pigment. Phycoerythrin pigment results in the red colour. Anthocyanins pigment gives red, purple and blue colours in many fruits and vegetables. Anthoxanthin pigment gives white or colorless to a creamy to yellow color to petals of flowers.

Thus, the correct answer is 'Phycocyanin and allophycocynanin.'

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Cyanobacteria are useful biofertilizers in fields of

  1. Wheat

  2. Maize

  3. Rice

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

Cyanobacteria are also called as Blue green algae. They are prokaryotic bacteria. They are nitrogen fixing bacteria. They are capable of fixing atmospheric nitrogen into ammonium compounds and making it available to the plants. They are useful bifertilizers in fields of rice for cultivation. They are used either free-living and in symbiotic association.

Thus, the correct answer is 'Rice.' 

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

In Nostoc, the enzyme nitrogenase occurs in

  1. Vegetative cells

  2. Heterocysts

  3. Only in hormogones

  4. Both A and B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Nostoc is a cyanobacteria. It has ability to fix atmospheric nitrogen. It converts nitrogen into ammonia. The heterocysts present in it are specialized cyanobacterial cells for nitrogen fixation. It contains enzyme nitrogenase. Nitrogenase is inactivated by oxygen. Hence, the heterocyst creates a micro anaerobic environment.
Thus, the correct answer is 'Heterocysts.'
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The similarity between cyanobacterium and bacterium is

  1. Presence of flagella

  2. Presence of 80S ribosome

  3. Presence of nucleoid

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There are many similarities between cyanobacterium and bacterium. They both posses saparophytic mode of life. They both lack true cell organelles. They both posses nucleoid instead of true nucleus. 

Thus, the correct answer is 'Presence of nucleoid.'

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Pigment containing membranous extensions in some cyanobacteria are

  1. Chromatophores

  2. Heterocysts

  3. Basal bodies

  4. Penumatophores
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In cyanobacteria, the pigment-containing membranous extensions that facilitate photosynthesis are called chromatophores (or thylakoids). Heterocysts are specialized cells for nitrogen fixation, not pigment storage.