Nitrogen Fixing Bacteria

Q. Match the columns and choose the correct answers

	I		II
a	Free living aerobic nitrogen fixers	1	Anabaena and Nostoc
b	Anaerobic nitrogen fixers	2	Pseudomonas denitrificans and Thiobacillus denitrificans
c	Nitrogen fixing cyanobacteria	3	Nitrosomonas and Nitrococcus
d	Denitrifying bacteria	4	Azotobacter and Beijerinckia
e	Nitrifying bacteria	5	Rhodospirillum

1. a - 5, b - 4, c - 1, d - 3, e - 2
2. a - 1, b - 2, c - 3, d - 4, e - 5
3. a - 2, b - 3, c - 4, d - 1, e - 5
4. a - 4, b - 5, c - 1, d - 2, e - 3

Q.

Which one of the following is not a bio fertilizer?

1. Mycorrhiza

2. Agrobacterium

3. Rhizobium

4. Nostoc

Q. Which bacteria convert ammonia to nitrite?

1. Nitrobacter
2. Pseudomonas
3. Nitrosomonas
4. Thiobacillus

Q.

What are some examples of nitrogen fixing bacteria?

Q. Frankia produces nodules on the roots of

1. leguminous plants like Alnus
2. non-leguminous plants like Alnus
3. leguminous plants like sweet pea
4. non-leguminous plants like sweet pea

Q.

The common nitrogen-fixer in paddy fields is?

1. Rhizobium

2. Oscillatoria

3. Azospirillum

4. Frankia

Q. Azolla is used as biofertilizer because it

1. Form massive biomass
2. Has association of nitrogen fixing Rhizobium
3. Possesses association with nitrogen fixing cyanobacteria
4. Has association with mycorrhiza

Q. A free living nitrogen fixing cyanobacterium which can also form symbiotic association with the water fern Azolla is

1. Tolypothrix
2. Chlorella
3. Anabaena
4. Nostoc

Q.

Which of the following is a symbiotic nitrogen fixing bacteria?

1. Azolla

2. Glomus

3. Azotobacter

4. Frankia

Q. Nitrifying bacteria convert ___to nitrate.

Q. Most plants obtain nitrogen from the soil in the form of

1. Nitrate
2. $NH{O}_3$
3. Free nitrogen Gas
4. Nitrogen

Q.

Question 13

What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?

Q. What is nitrification?

Q. Frankia is a free living soil organism, but leads symbiotic life in the root of leguminous plants.

1. True

2. False

Q. Which of the following bacteria converts ammonia to nitrite?

1. Nitrobacter
2. Pseudomonas
3. Nitrosomonas
4. Thiobacillus

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

Q.

Which of the following is a symbiotic nitrogen fixing bacteria?

1. Azolla

2. Glomus

3. Azotobacter

4. Frankia

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

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

Q.

Assertion — Rhizobium lives in the root nodules of leguminous plants.
Reason — It fixes nitrogen through a symbiotic relationship.

1. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

2. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.

3. If Assertion is correct but Reason is incorrect.

4. If Assertion is incorrect but Reason is correct.

Q. An example of endomycorrhiza is

1. $Rhizobium$
2. $Agaricus$
3. $Glomus$
4. $Nostoc$

Q.

Biofertilizer include

1. nitrogen fixing bacteria

2. nitrogen fixing cyanobacteria

3. both bacteria and cyanobacteria

4. bacteria, cyanobacteria and mycorrhizal fungi

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

Q.

What is the common nitrogen fixer in paddy fields?

Q. Find the group of bacteria in which all are nitrogen fixing.

1. Rhizobium, Azotobacter, Nostoc
2. Nitrosomonas, Streptococcus, Lactobacillus
3. Clostridium, Rhizobium, Lactobacillus
4. Nitrobacter, Streptobacillus, Lactobacillus

Q.

Name the nitrogen-fixing bacteria present in root nodules of leguminous plants.

Q.

What is an endosymbiont? Give an example.

Q. A prokaryotic autotrophic nitrogen fixing symbiont is found in:

1. Pisum
2. Cicer
3. Alnus
4. Cycas

Q. Azolla is used as biofertilizer because it

1. Form massive biomass
2. Has association of nitrogen fixing Rhizobium
3. Possesses association with nitrogen fixing cyanobacteria
4. Has association with mycorrhiza

Q. Which among the following is a free-living nitrogen-fixing anaerobe?

1. Beijerinckia
2. Rhodospirillum
3. Azotobacter
4. All of these

Q.

Find out the correct match

a. Cyanobacteria - biopestcide

b. Mycorrhiza - solubilisation of phosphate

c. Bacillus thuringiensis - insecticidal property

d. Single cell protein - Rhizobia

1. c and d

2. a and b

3. b and c

4. a and c