Nitrogen Fixing Bacteria

Q.

Which of the following species does not have the ability to fix atmospheric nitrogen?

1. Azotobactor

2. Anabaena

3. Nostoc

4. Spirogyra

Q.

Which enzyme is involved in biological nitrogen fixation?

Q.

Pseudomonas bacteria convert nitrates into nitrogen gas.

1. True
2. False

Q.

One of the free-living anaerobic nitrogen fixer is:

1. Azotobacter

2. Beijerinckia

3. Clostridium

4. Rhizobium

Q.

Why do nitrogen fixation nodules contain large amounts of leghaemoglobin?

Q. Which nitrogen fixing BGA is present in coralloid roots of Cycas?

1. Azolla
2. Nostoc
3. Anabaena
4. Both b and c

Q.

One of the free-living anaerobic nitrogen fixer is:

1. Azotobacter

2. Beijerinckia

3. Clostridium

4. Rhizobium

Q.

Some blue-green algae can be used as biofertilizers because they are:

1. Photosynthetic

2. Surrounded by mucilage

3. Growing everywhere

4. Can fix atmospheric nitrogen

Q. All are free-living nitrogen fixers except:

1. Azotobacter
2. Beijernickia
3. Rhodospirillum
4. Rhizobium

Q.

Which of the following species does not have the ability to fix atmospheric nitrogen?

1. Azotobactor

2. Anabaena

3. Nostoc

4. Spirogyra

Q. We need to use nitrogenous fertilisers even though our atmosphere contains 78% nitrogen because

1. 78% Nitrogen is not enough for the amount of crops grown by human beings
2. Plants cannot use nitrogen in the gaseous state
3. Plants need some agent to mix the atmospheric nitrogen in the soil
4. All of the above

Q. Rhizobium has a relationship with the roots of:

1. Sweet clover
2. Lentils
3. Both A and B
4. Maize

Q.

4.Which of the following is a denitrifying bacteria?

1. Nitrobacter

2. Nitrosomonas

3. Pseudomonas

4. Rhizobium

Q. Rhizobium has a relationship with the roots of:

1. Sweet clover
2. Lentils
3. Both A and B
4. Maize

Q. Assertion (A): Nitrogenase enzyme gets inactivated in the presence of oxygen, yet nitrogen fixation occurs in aerobic cells of legume nodules
Reason (R): Leghaemoglobin allows presence of oxygen just sufficient for cellular respiration only

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true and R is not the correct explanation of A
3. A is true but R is false
4. Both A and R are false

Q.

Nitrifying bacteria:

1. Reduce nitrates to free nitrogen

2. Oxidize ammonia to nitrates

3. Convert free nitrogen to nitrogen compounds

4. Convert proteins into ammonia