Soil Fertility and Nitrogen Fixation

Q.

What kind of relationship is between rhizobium and the plant?

Q. Question 1 (b)
Blue green algae fix ___ directly from air to enhance fertility of soil.

Q.

Which of the following is a non-symbiotic biofertilizer?

1. VAM

2. Azotobacter

3. Anabaena

4. Rhizobium

Q. The nutrients required in small quantities for the plant growth are called .

Q. Answer the following question based on the image given below.
_________ bacteria lives in the root nodules and the relationship it shares with the roots of the leguminous plants is called as ________.

1. Rhizobium, beneficial relationship

2. Lactobacillus, commensal relationship

3. Rhizobium, symbiotic relationship

4. Yeast, harmful relationship

Q.

In organic farming, some blue-green algae can be used as biofertilisers because:

1. They are photosynthetic

2. They have mucilage

3. They can fix atmospheric nitrogen

4. They grow everywhere

Q.

How does lightning fix nitrogen in the atmosphere ?

Q.

Which of the following is a micro-nutrient?

1. Copper

2. Calcium

3. Magnesium

4. Potassium

Q. What is incorrect about nitrogen fixing bacteria?

1. They convert gaseous nitrogen to a substance utilisable by plants.
2. They convert gaseous nitrogen to ammonia $\left(N{H}_4^{+}\right)$.
3. They convert gaseous nitrogen to nitrite $\left(N{O}_2^{-}\right)$.
4. They make the soil fertile.

Q.

______ nutrients are needed in small quantity for plants and are called ______.

Q. Assertion :Leguminous plants are nitrogen fixers Reason: Leguminous plants have Rhizobium in their root nodules

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which of the following is a free living nitrogen fixing bacteria present in the soil?

1. Nitrosomonas
2. Pseudomonas
3. Rhizobium
4. Azotobacter

Q. Explain the nitrogen cycle.

Q. How is fixation of nitrogen brought in plants during lightning?

Q.

The minerals required by the plants in very small quantities are called

1. macronutrients

2. manures

3. fertilizers

4. micronutrients

Q. Rhizobium fixes nitrogen by:

1. Converting gaseous nitrogen to ammonia
2. Converting gaseous nitrogen to nitrite
3. Converting gaseous nitrogen to nitrate
4. Liquifying atmospheric nitrogen

Q. The nitrogen molecules present in the air can be converted into nitrates and nitrites by :

1. nitrogen fixation
2. cereal plants
3. carbon fixation
4. industries in the form of by ctprodu

Q.

Draw diagram of ​

(i) nitrogen cycle ​

Q. Nitrogen fixation is inhibited by oxygen. However, in aerobic nitrogen-fixing bacteria, nitrogen is fixed in the presence of oxygen. Nitrogenase in such organisms is protected by which one of the following mechanisms.

1. Channelizing oxygen to form ozone.
2. Removal of oxygen by metabolic activity.
3. Utilizing oxygen for membrane remodeling.
4. Utilizing oxygen for synthesis of pentapeptide chain in peptidoglycan.

Q. Liquid nitrogen is used as a refrigerant to preserve biological specimens.

1. True
2. False

Q. Nitrifying bacteria convert ___to nitrate.

Q.

Nitrogen is used in the manufacture of ammonia by the ______ process.

Q. Select all microbes that help in nitrogen fixation.

1. Blue-green algae
2. Rhizobium
3. Rhizopus
4. Amoeba

Q.

Which of the following is not a macronutrient?

1. Nitrogen

2. Sulphur

3. Manganese

4. Calcium

Q. The nitrogen molecules present in air can be converted into nitrates and nitrites by:

1. A biological process of nitrogen fixing bacteria present in soil
2. A biological process of carbon fixing factor present in soil
3. Any of the industries manufacturing nitrogenous compounds
4. The plants used as cereal crops in field

Q. For Nitrogen fixation in soil we may use ______________.

1. Cyanobacteria
2. Protozoans
3. Nematodes
4. Wheat plants

Q. Mention any two nitrifying bacteria.