Nitrogen Fixation

Q.

Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not add nitrogenous fertilisers to the crops. Why?

1. These plants produce manure for themselves.

2. These plants make more nitrogen internally.

3. Nitrogen is harmful for these plants.

4. The bacteria present in the roots fix nitrogen.

Q.

Why is nitrogenous fertilizers not added in soil in which leguminous plants are grown?

Q.

What are multiple cropping systems?

Q.

Why nitrogen is important for living organism?

Q.

Question 13
Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilisers during cultivation. Why?

Q. Name the bacteria which convert nitrogen gas of air into nitrogen compounds

Q.

Why nitrogen fixation is important?

Q. Name any one plant which has nitrogen fixing rhizobium bacteria in it's roots

Q.

The first stable product of fixation of atmosphere nitrogen in leguminous plants is?

1. NO₃^-

2. NO₂^-

3. Glutamate

4. Ammonia

Q.

What is the role of nitrogen-fixing bacteria in the nitrogen cycle?

Q.

Rhizobium is a nitrogen-fixing bacteria found in the roots of (i)______ and have a (ii)_______ relationship with them.

1. (i) all plants

   (ii) saprophytic

2. (i) pulses

   (ii) symbiotic

3. (i) mango

   (ii) parasitic

4. (i) mango

   (ii) symbiotic

Q.

What Is the Largest Reservoir of Nitrogen?

Q.

In nitrogen cycle, nitrite is converted to nitrate by?

Q.

Pollen grains are male gametes.

1. True
2. False

Q.

Why nitrogen fixation is an energy-consuming process?

Q.

Wind-pollinated flowers produce pollen grains in large quantity.

1. True
2. False

Q. What are the Importance of symbiotic relation for farmers?

Q.

Rhizobium bacteria fix nitrogen and are present in the roots of all plants. True or false?

1. True

2. False

Q.

Can humans live without nitrogen?

Q.

Plants cannot absorb nitrogen in the gaseous form from atmosphere directly.

1. True

2. False

Q.

Which type of flower stigma is rough and sticky?

Q. Why farmers sometimes grow leguminous plant crops in one season and non leguminous plants in another season?

Q.

Which bacteria fixes nitrogen in leguminous plant?

Q.

Nitrogen is required for protein synthesis in plants.

1. True
2. False

Q.

What are the main steps in nitrogen cycle? Mention the microbes involved in each step.

Q. Why plants cannot absorb molecular nitrogen from the atmosphere?

1. Nitrogen is highly reactive
2. Abundance in the atmosphere inhibits absorption
3. Nitrogen is highly stable
4. Nitrogen is toxic

Q. What do you mean by biological nitrogen fixation?

1. Conversion of atmospheric nitrogen into useful nitrogen compounds by bacteria and algae.
2. Conversion of nitrogen compounds into free nitrogen by bacteria and algae.
3. Conversion of nitrogen compounds into ammonia by chemical process.
4. Conversion of atmospheric nitrogen into useful nitrogen compounds by lightning.

Q.

The nitrogen cycle involves bacteria capable of changing proteins to ammonia is

1. Bacteria of decay

2. Denitrifying bacteria

3. Nitrogen-fixing bacteria

4. Ammonifying bacteria

Q.

Where we can see rhizobium bacteria?

Q.

After harvesting crops, certain types of plants are preferably grown on the land to replenish the soil of depleted nutrients. This helps in reducing the dependence on artificial nitrogenous fertilizers.

Which of the following plants should be grown? (You may choose more than one option)

1. Rajma

2. Banana

3. Peas

4. Rice