Answer:
<em>The correct option is cell surface markers.</em>
Explanation:
The immune cells of our body detect foreign particles and generate responses so that our body can get rid of them. The foreign particles are often termed as antigens.
The immune cells such as antibodies possess cell surface receptors which detect the foreign objects or antigens. When the cell surface receptors detect any antigen they immediately recognize that a foreign particle has invaded the body and they then identify it and start to generate response.
When it's hot or when the organism starts sweating a lot, this causes an amount of water to be lost from the body. Water is important for the organism to survive and it's absence wi lead to death, therefore Osmoreceptors cells in the hypothalamus in the brain, sends signals to increase the rate of water re-absorption by the kidney. This causes the urine to be of a low volume and more concentrated. This allows enough water to be used by the body as a lot has been lost during sweating.
Osmosis<span> is the phenomenon of the movement of Solvent molecules from lower solute conc. to higher solute conc. through a semi-permeable membrane to make solute conc. equal on both sides.</span>
