
<h2>Fixation</h2>
Nitrogen in its gaseous form (N2) can’t be used by most living things. It has to be converted or ‘fixed’ to a more usable form through a process called fixation. There are three ways nitrogen can be fixed to be useful for living things:
<h3>Biologically: </h3>
Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants. Legumes (such as clover and lupins) are often grown by farmers because they have nodules on their roots that contain nitrogen-fixing bacteria.
<h3>Through lightning: </h3>
Lightning converts atmospheric nitrogen into ammonia and nitrate (NO3) that enter soil with rainfall.

Answer: There are several problems associated with handling of the squid.
Explanation:
Squid is a deep sea creature which becomes enormously big in size and difficult in handling in artificial water body or aquaculture.
It consumes and requires huge amount of food in the pre-larval stages typically phytoplankton and it becomes difficult to provide such food to them.
The maintenance of temperature, and salinity for the squid in aquaculture is difficult.
The sticky arms of the squid adhere to the surface of tub or human handler making it difficult to handle and can be poisonous to humans too.
Answer:
Water vapor
Explanation:
Warm air cooling causes moisture called water vapor which creates water droplets called condensation.
<h2>Answer:</h2>
The correct option is B which is micropyle.
<h3>Explanation:</h3>
- Generally micropyle is known as the opening in the ovule or egg from which sperm enters the egg.
- But at the time of germination it is used to absorb water and nutrients.
- It is the micropyle from which the root emerges from the seed.
Answer:
D. The nerves exit the central nervous system in the head and from the lumbar spine.
Explanation:
The preganglionic neurons transmit the nerve impulses through the cranial or spinal nerves that arise from the brain, to the postganglionic neurons from where the nerve fibers that relay these nerve signals to the different viscera and effector organs, located along the spinal cord