Some proteins within a cell can be viewed with

Some proteins within a cell can be viewed with the "Electron microscope".

Explanation:

An electron microscope is a laboratory microscope with a singular beam that uses electrons to refract the surface of objects and picture an image. They can improve the reach of light photons. So, they mean a really big improvement. They are used to study molecules, microorganisms, crystals and more tiny objects. Thus, that is why electron microscopes can reach proteins inside the cells.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.