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.
Answer:
Change in an organism's environment forces the organism to adapt to fit the new environment, eventually causing it to evolve into a new species. ... Organisms become isolated as a result of environmental change. The cause of isolation can be gradual, like when mountains or deserts form, or continents split apart.
Explanation:
The best answer is B - the fish die.
Acid rain flows through soils. If the soil part of a watershed, aluminum is released from the soil and into the streams and lakes located in that watershed.
This lowers the pH in the lake from between 6 and 8 (which is the normal pH in lakes and streams) to less than 5.
Both increase of aluminum and lower pH are directly toxic to fish and they kill off fish populations
