The rigth answer is D.
The wavefront or wavefront is an equal phase surface of a wave, i.e., these points have the same travel time from the source. The concept is used to describe the propagation of waves such as sound or electromagnetic radiation (light, radio waves, etc.). In a homogeneous and isotropic medium, in which the waves propagate without deformation, two types of particular waves are distinguished according to whether the wavefronts are spheres (spherical wave) or planes (plane wave).
I think the answer is A. vacuole
to keep your body functioning and active depending on the hormones
Answer:
The form of cell to cell signalling that is been used is ENDOCRINE.
Explanation:
There are four ways by which cell signalling occur in the body, these are: endocrine, paracrine, autocrine and direct signalling.
Endocrine signalling is the biochemical process by which hormone secreting glands release hormones into the blood streams and that hormone has effects on target organs that are located far away from it. Endocrine hormones are usually stable and their effects usually last for long time.
