The best answer is D.
Hormones are chemical messengers secreted mostly into blood and also extracellular fluid by specialized tissue of the endocrine system and affect the functioning of other tissues or cells.
Most hormones circulate in blood and come in contact with essentially all cells, but a particular hormone will only affect a limited number of cells, which are termed as target cells to that hormone.
A target cell responds to a particular hormone because it bears receptors for that hormone.
For example the red blood cells have receptors for the hormone called insulin which is produced by the pancreas. The red cells are able to take in glucose when their receptors bind to insulin.
Although nitrogen gas makes up 78% of the atmosphere, we can't use it because nitrogen atoms must be broken apart first before. This nitrogen is very much packed and bonded with its atoms and would be useless to use since it can't be used for plants.
I am pretty sure that it is D
With decomposition, the final deposition of particles(sediments) usually occurs at the mouth of a stream. Then a process called horizontal sorting occurs where the sediments that were once carried down are arranged from big to small. Decomposition in streams takes time so the speed of the water and wind should not affect it nor should gravity or the direction. Streams cannot change direction either unless human involement occurs
Hope this helps :)
I don't get it either I just want the brainy points lol
Answer:
Natural selection
Explanation:
According to Darwin's theory, natural selection is the process by which individuals better adapted to their environments have more chances to survive and reproduce, and thereby their descendants will be better represented in the next generation. This mechanism exploits the existence of natural variation among members in the population which is used to select those individuals that are better adapted (i.e., with a higher adaptive fitness) for their environments. Natural selection is a key mechanism of evolution by which species change across time.