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: A,B and C
Explanation
This is a biology worksheet all about it hope this helps
A variation is a reference to the differences or deviations, such as the structure and form, as for crossing over is the exchange of genetic material between the non-sister chromatids of the homologous chromosomes during meiosis.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's metabolic activities