Tag: microbes in human welfare

Quizzes (8) Questions (107)

Questions Related to microbes in human welfare

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

Which was the first photosynthetic organism?

  1. Green algae

  2. Red algae

  3. Cyanobacteria

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

Photosynthesis is the process by which light energy from the sun is used to synthesise sugars from carbon dioxide, releasing oxygen as a waste product. In primitive days, cyanobacteria were only the primary producers because the redox structure of oceans favoured them to fix nitrogen and also they had the capacity to use water as the source of electrons in photosynthesis. They made the atmosphere oxygen rich and allowed the appearance of aerobic organisms. 

Thus, the correct answer is option C.

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

Which one of the followings is not the characteristic feature of cyanobacteria?

  1. They are always multicellular.

  2. They form colonies.

  3. They form blooms in polluted water bodies.

  4. They can fix atmospheric nitrogen.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cyanobacteria are unicellular prokaryotes that photosynthesise. They form huge colonies that appear as algal bloom in polluted waters. They can fix nitrogen from the atmosphere by means of specialised structures called as heterocysts.

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

Cow dung is appropriately used as

  1. Manure

  2. Perfume

  3. Medicine

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

Cow dung is available in plenty in India. It is used as manure or pattings for fuel. The cow dung solution has antifungal and insecticide properties. The application of cow dung also improves soil salinity and alkalinity. The presence of this manure helps in better nitrogen fixation through rhizobia.

So, the correct answer is option A.

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

During rainy seasons, the ground becomes slippery due to dense growth of

  1. Lichens

  2. Bacteria

  3. Green algae

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

Blue green algae or cyanobacteria synthesize a gelatinous mass around themselves, enclosing multiple filaments. This causes the surface area on which they thrive to be slippery

So, the correct answer is 'cyanobacteria'

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

Biofertilizers

  1. Kill pests

  2. Prevent pest growth

  3. Retain soil fertility

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

Biofertilizers are used because they increase soil fertility, crop productivity, and production. Use of biofertilizers is both economical as well as environment-friendly. They remain symbiotically associated with the roots while some are free living. They solubilize the undissolved minerals.

So, the correct answer is option C.

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

True nucleus and mitochondria are absent in

  1. Cyanophyceae

  2. Chlorophyceae

  3. Myxomycetes

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

Prokaryotes are unicellular organisms. They lack membrane-bound organelles like mitochondria, golgi apparatus. They also lack true nucleus. Instead, they have nucleoid or incipient nucleus. Nucleoid is an undifferetiated, unorganised, fibrillar nucleus without any limiting membrane. They have ribosomes in the cytoplasm. Examples include bacteria, Cyanophyceae. 

Thus, the correct answer is 'Cyanophyceae.'

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

Which one of the following can fix nitrogen?

  1. Vaucheria

  2. Spirogyra

  3. Nostoc

  4. Ectocarpus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The atmospheric nitrogen is not available to plants. There are some nitrogen-fixing bacteria which converts atmospheric nitrogen into ammonia which is readily available to plants. Nostoc is a cyanobacterium. It has the ability to fix atmospheric nitrogen. The heterocysts present in it contains nitrogenase enzyme. These are specialized for nitrogen fixation. 
Thus, the correct answer is 'Nostoc.'
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Some blue green algae are used as biofertilizers because they

  1. Are photosynthetic

  2. Have mucilage

  3. Grow everywhere

  4. Fix nitrogen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The atmospheric nitrogen is not available to plants. There are some nitrogen fixing bacteria which converts atmospheric nitrogen into ammonia which is readily available to plants. Some blue green algae like Anabaena and Nostoc have the ability to fix the atmospheric nitrogen. They are free-living nitrogen fixing bacteria. Hence, they are used as biofertilizers in the field of rice. 
Thus, the correct answer is 'Fix nitrogen.'
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Blue green algae are

  1. Actinomycetes

  2. Eukaryotes

  3. Prokaryotes

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

Prokaryotes are unicellular organisms without membrane-bound organelles like mitochondria, golgi complex. They lack true nucleus. Instead, they have nucleoid, genetic material without nuclear envelope. The examples of prokaryotes include bacteria, Cyanobacteria (Blue green algae). Blue green algae are photosynthetic bacteria.

Thus, the correct answer is 'Prokaryotes.'