Answer & explanation:
The cell was discovered in 1669 by the English scientist Robert Hooke when looking at a piece of tissue in a two-lens microscope. Hooke was able to visualize small cavities in the experiment piece, then naming such cell cavities.
Only a century and a half after the discovery of the cell, that the Cell Theory was launched, replacing the theory of spontaneous generation (or abiogenesis).
Before that, many scientists were already busy understanding the structure and functioning of the cell, generating knowledge that became fundamental to the development of biology, specifically cytology, a branch of science that studies the structure, functions and development of cells.
Answer:
these are all correct
Explanation:
i just took the quick check
Answer:
The barrier functions to regulate the chemical composition of the extracellular fluid surrounding the brain cells.
Explanation:
Blood-brain barrier
It is a very selective semipermeable membrane , hence allow some specific substance to pass via it . This barrier separates the extracellular fluid in the central nervous system and the circulating blood from the brain .
<u>The barrier is composed of the endothelial cells .</u>
Passive diffusion is shown in this system , and allows molecules like the water , glucose , amino acid to pass .
It regulates the chemical composition of the fluid of brain cell .
