D is ans becauseit convert
Explanation:
convert nitrogen gas in the atmosphere to ammonia. Nitrifying bacteria convert ammonia to nitrites or nitrates.
Answer:
Sperm-egg interaction
Explanation:
The formation of fertilization envelope is well-studied on the model system- sea urchin. It has been shown that, the fertilization envelope is formed after the initial sperm-egg interaction from the egg surface vitelline envelope and the paracrystalline protein fraction which is derived from cortical granules. Secretion from cortical granules, prevents polyspermy.
The answer to this question would be D (DNA). It can be found in the nucleus of a cell and contains the entire genetic information of a whole.
The seeds are enclosed because it's the plants way of protecting them.
