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.
There are so many examples for that in different areas, like organic germanium compounds experiment carried out in our lab recently.
Here's one link: http://www.alfa-chemistry.com/products/organic-germanium-24.htm
4 cells will result. Each cell will have 20 Chromatids which is half a chromosome. once sexual reproduction takes place, these 20 chromatids will match with those from the other parent cell to form chromosomes
Answer:
<h2>False</h2>
Explanation:
Natural killer cells (NK cells) are a type of lymphocyte and also a component of innate immune system. NK cells play various functions in immune system and they play a major role in the host-rejection in virally infected cells.
NK cells are activated in response to interferons and also by various other responses. NK cells work to by secreting IFNγ and TNFα. Natural killer cells play a very important role in early host defense against viruses.
