Nitrogen fixation is carried out by:

1.  bacteria 2.  fungi
3.  protists 4.  algae

Subtopic:  Microbes as Biofertilizer |
 81%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


The figure shows mycorrhiza [white threads] in rhizosphere. Identify the correct statements regarding this mutualist symbiotic relationship:
Statement I:  The plant makes organic molecules such as sugars by photosynthesis and supplies them to the fungus. The fungus supplies to the plant water and mineral nutrients, such as phosphorus, taken from the soil.
Statement II:  Mycorrhizal plants are often more resistant to diseases, such as those caused by microbial soil-borne pathogens.
 
1.  Statement I is correct but Statement II is incorrect
2.  Statement I is incorrect but Statement II is correct
3.  Statement I is correct and Statement II is correct
4.  Statement I is incorrect and Statement II is incorrect
Subtopic:  Microbes as Biofertilizer |
 87%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


Arbuscular mycorrhizas are formed only by fungi in the division:

1. Ascomycota 2. Glomeromycota
3. Basidiomycota 4. Microsporidia
Subtopic:  Microbes as Biofertilizer |
 56%

To unlock all the explanations of this course, you need to be enrolled.

Hints

advertisementadvertisement

The figure shows Azolla [mosquito fern, duckweed fern, fairy moss, water fern]. The plant is ecologically important because:
Statement I:  They form a symbiotic relationship with the cyanobacterium Anabaena azollae.
Statement II:  Anabaena azollae is an extracellular endosymbiont (living outside the host's cells) which fixes atmospheric nitrogen.
 
1.  Statement I is correct but Statement II is incorrect
2.  Statement I is incorrect but Statement II is correct
3.  Statement I is correct and Statement II is correct
4.  Statement I is incorrect and Statement II is incorrect
Subtopic:  Microbes as Biofertilizer |
 78%

To unlock all the explanations of this course, you need to be enrolled.

Hints

Match each item in Column I [Diazotroph] with the feature in Column II and select the correct answer from the codes given below:

 

COLUMN I

 

COLUMN II

A.

Cyanobacteria

a.

Actinorhizal symbiont

B.

Frankia

b.

Do not form nodules

C.

Rhizobium

c.

Free-living nitrogen fixer

D.

Azotobacter

d.

Legume symbiont

Codes

A B C D
1. a b c d
2. b a c d
3. a b d c
4. b a d c
Subtopic:  Microbes as Biofertilizer |
 58%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


In paddy fields, important biofertilizers are:

1.  Cyanobacteria 2. Rhizobium
3. Frankia 4. Glomus
Subtopic:  Microbes as Biofertilizer |
 71%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

What advantage does the mycobiont get in the mycorrhizal symbiotic relationship?
1. Adequate uptake of water
2. More availability of minerals like phosphorus
3. Availability of carbohydrates for energy
4. Resistance to diseases, drought, and salinity

Subtopic:  Microbes as Biofertilizer |
 53%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.