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.

What are nitrogen-fixing bacteria?

Q.

What will happen if nitrogen fixation does not take place?

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

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

Q. Azolla has a symbiotic association with

1. Rhizobium
2. Anabaena
3. Nostoc
4. Azospirillum

Q.

What is the reduction of nitrogen to ammonia by living entities called?

Q.

Which of the following is a bacterium involved in denitrification?

1. Pseudomonas

2. Nitrobacter

3. Azotobacter

4. Nitrosomonas

Q.

What happens during nitrogen fixation?

Q.

Azolla is used as a biofertilizer because:

1. It has an association with nitrogen fixing Cyanobacteria

2. It has an association with nitrogen fixing Rhizobium

3. It multiplies very quickly to produce massive biomass

4. It has an association with mycorrhiza

Q. Which of the following organisms helps in the process of changing nitrite to nitrate?

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

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. Nostoc
4. Anabaena

Q. Rhizobium has a relationship with the roots of:

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

Q.

What is denitrification and nitrification?

Q. WHICH SUBSTANCE IS PRESENT IN ROOT NODULES OF LEGUMINOUS PLANTS?

Q. In the following list, how many free-living diazotrophs are there?
Azobacter, Beijerenckia, Rhodospirillum, Bacillus, Anabaena, Nostoc.

1. Four
2. Six
3. Two
4. Three

Q. Nitrifying bacteria ___________________.

1. Oxidize ammonia to nitrates
2. Convert free nitrogen to nitrogen compounds
3. Convert proteins into ammonia
4. Reduce nitrates to free nitrogen

Q. An example for symbiotic bacteria is

1. Erwinia amylovora
2. Rhizobium leguminosarum
3. Xanthomonas compestris
4. Agrobacterium tumefaciens

Q.
Name a photoautotrophic bacterium.

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

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

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

Q. Some blue green algae are used as biofertiliser because they can

1. Fix nitrogen
2. Secrete mucilage
3. Perform photosynthesis
4. Grow everywhere

Q. Rook in some Gymnospeums have fungal and algal association. Give examples, their names and role in plants.

Q. Which of the following fern is an excellent biofertilizer?

1. Azolla
2. Marsilea
3. Salvinia
4. Pteridum

Q. the measleson and stahls experment is continued for four generations in bacteria the ratio of N15 N15 nitrogen 15 nitrogen 14 nitrogen 14 nitrogen 14 containing DNA in 4th generation would be