Answer:
The atmosphere is the largest reservoir of the nitrogen as it is composed of 78% of Nitrogen. Although 78%, this is not used by the organisms directly as the nitrogen molecule exists in nature in the form of divalent joined via triple bonds.
These triple bonds require a great amount of energy to be broken and used. Only a few prokaryotic organisms called nitrogen-fixing bacteria have the capability to break these triple bonds as they contain enzymes-nitrogenase complex which converts the atmospheric nitrogen to usable forms like ammonia, nitrates and nitrites. About 92% of the atmospheric nitrogen is fixed through this way rest through thunderstorms and Haber's process.
Thus, nitrogen-fixing bacteria is the answer.
Answer:
In quiet breathing inspiration involves muscular contractions and expiration is passive.
Explanation:
Respiration process involves two different stages, inspiration - inhalation- and expiration - exhalation-.
During inspiration, the diaphragm <u>contracts</u> and goes down, while intercostal muscles also <u>contract</u> and go up. These actions enhance the size of the thoracic box and <u>reduce internal pressure</u>. As a result, air flows in and fills the lungs.
During expiration, the <u>diaphragm relaxes</u> and the volume of the thoracic box diminishes, which causes the <u>pressure inside to increase</u>. In consequence, the lungs contract and the air is expulsed outside.
Answer:
D) Mouth, pharynx, esophagus, stomach, small intestine, large intestine.
Explanation:
Food is ingested in the mouth, passes through the pharynx that connects the mouth to the esophagus. It moves down the esophagus by parastalsis. It is further digested in the stomach, absorbed in the small intestine and indigestible material together with fibre is passed to the large intestine where its either digested by freindly bacteria or eliminated as waste by defecation.
Answer:
A if not A then its D
Explanation:
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