Answer:A) Nitrogen
Explanation: nitrogen cycle ensures the movement of nutrients through the biosphere.it ensures that nitrogen is constantly reused and made available.
Nitrogen gas is available in the atmosphere but plants and animals cannot use it in that form.it must be converted to compounds such as ammonia or nitrate.
It is gotten from the atmosphere during rainfalls where it Is broken down and combines with oxygen to from nitrogen peroxide.
Nitrogen can also be fixated into ammonia by saprophytic bacteria.
Also when plants die their body tissues are broken down to form ammonia.ammonia can be oxidized into nitrates and nitrite which plants can use.
Nitrites can be released back into the atmosphere through denitrifying bacteria and the cycle continues.
Easy,
1- Proteins gives us energy
2- Proteins help us in cell repair and they take part in cell reproduction
3- Proteins contain powerful particles that diffuses and give energy to do work
4- Proteins are powerful
Stream channeled flow of water,regardless of size
Answer: By Hormonal action and Nervous coordination
Explanation:
Hormones are substances produced by one tissue and conveyed by the bloodstream to another to effect physiological activity. Homeostasis is the maintenance of a stable internal environment in the body.
Body systems such as digestive, circulatory, excretory systems etc, all are coordinated to achieve a STABLE INTERNAL ENVIRONMENT by the aid of HORMONES AND/OR NERVOUS COORDINATION.
For Example: the vasodilation of blood vessels during hot weather, and the opposite action of vasoconstriction during cold weather are both controlled by Hormonal action and nervous coordination which leads to a stable body temperature preventing excess heat accumulation.
Also, Nervous system controls the body systems, such that the muscle contractions are joined to actions like sweating, breathing, respiration etc
So, to maintain homeostasis hormonal action and Nervous coordination is necessary.
