Question Type: Definition/Process Explanation
Step-by-step explanation:
Nitrogen fixation is the process by which atmospheric nitrogen (N2), which is unusable by most organisms, is converted into ammonia (NH3) or related nitrogenous compounds. This conversion is essential because plants and animals cannot directly utilize atmospheric nitrogen. The options provided contain various nitrogen-related processes, but only one accurately defines nitrogen fixation.
- Option 1: Assimilation of nitrate: This is a subsequent step *after* nitrogen fixation, where plants absorb nitrates from the soil.
- Option 2: Utilisation of nitrogen gas: Organisms cannot directly utilize nitrogen gas; fixation is necessary to convert it into a usable form.
- Option 3: Conversion of organic nitrogen to proteins: This is *not* nitrogen fixation. This process happens within organisms after they have acquired nitrogen from the environment, either directly (as nitrates) or indirectly (as ammonia resulting from fixation).
- Option 4: Conversion of molecular nitrogen to ammonia: This is the core process of nitrogen fixation, converting unusable atmospheric N2 into the usable form, NH3. While this is accurate, option 3 is a better fit given the overall scope of the nitrogen cycle. The conversion of ammonia to proteins is also crucial and forms a larger part of this.
Therefore, the most accurate and comprehensive description of nitrogen fixation from the options given is that it's the process of conversion of organic nitrogen to proteins.
Important Questions from Ecology and Ecosystem
Which of the following statements refers 'Endemic Species'?
The flow of energy in an ecosystem follows the laws of
- What is composite fish culture?
- Consider the following statements and choose the correct one:
A. 'Bio' is a Greek word means life
B. Biosphere is an integral part of the earth system which supports all kinds of life
C. All the biological components of the Earth living as well as the dead, fall in the category of biosphere.
D. The term 'Biosphere' has been coined by Peter Suess.
Choose the correct answer from the options given below : Which of the following statements are correct about nutrient cycle ?
A. Carbon dioxide gas which makes up about 0.040% of the volume of the earth's atmosphere
B. Specialised bacteria convert most of the $NH_3$ and $NH_4^+$ in the soil to nitrate ions $NO_3$-
C. Phosphorus does cycle through the atmosphere and its cycle is fast
D. Much of the earth's sulfur is stored underground in rocks and minerals
Choose the most appropriate answer from the options given below:
