Tag: microbes in human welfare

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Questions Related to microbes in human welfare

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.'

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

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

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.

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

Members of which algal class impart red colour to red sea?

  1. Cyanophyceae

  2. Rhodophyceae

  3. Phaeophyceae

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

The red sea is the saltiest sea and connects to the ocean without any river meeting the sea. It is named so because of the abundant occurrence of red coloured planktonic cyanophyceae called Trichodesmium erythraeum. This cyanophyceae imparts red colour to red sea. This results in the algal bloom or red bloom.

Thus, the correct answer is 'Cyanophyceae.'

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

I. Unicellular, colonial, filamentous, marine or terrestrial forms.
II. The colonies are surrounded by a gelatinous sheath.
III. Some can fix atmospheric nitrogen in specialized cells called heterocysts.
IV. They often form blooms in water bodies.
These above characters are seen in

  1. Archaebacteria

  2. Cyanobacteria

  3. Chrysophytes

  4. Dinoflagellates

  5. Slime Moulds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cyanobacteria are also called as Blue green algae. They are unicellular, colonial, filamentous prokaryotes. They are found in marine and terrestrial habitats. The colonies are surrounded by a gelatinous sheath. They are photosynthetic bacteria. They often form blooms in water bodies and results in eutrophication. Some Cyanobacteria like Nostoc can fix atmospheric nitrogen in specialized cells called heterocysts and make it available to plants.

Thus, the correct answer is 'Cyanobacteria.'

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

Azolla possesses symbiotic association with

  1. <p>Anabaena</p>

  2. <p>Nostoc</p>

  3. <p>Azospirillum</p>

  4. <p>Rhizobium</p>
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Azolla is a small aquatic fern that maintains a symbiotic relationship with the cyanobacterium Anabaena azollae. This bacterium lives in the leaf cavities of the fern and fixes nitrogen for the plant.