The correct options are as follows:
1. C
Homeostasis is the process by which living organisms maintains constant internal environment. Maintaining homeostasis is very important because the survival of the living organism depend on it. In order to maintain homeostasis, the amount of wastes, nutrients and water that is in an organism must be controlled and maintained at optimum level.
2. A.
An organism that can not maintain an homeostasis will die. This is because, lack of homeostasis will disrupt the biochemical reactions which sustains the life activities of the organism and once the biochemical reactions that produce life energy can no longer take place the organism will die.
3. A.
For both unicellular and multi cellular organisms, when they are exposed to water containing no salt, much of the water will move into their cells. This happened because, the level of salt in the interior of the living cells is higher and so the water will move from the medium which has no salt to the inside to the cell where there is salt. This process is known as osmosis. In osmosis water move through a semi permeable membrane from the region of low salt concentration level to the region of higher salt level concentration.
4. D.
Cells in living organisms are able to maintain homeostasis by specializing in specific functions and by working together in cooperatively. Each cell has its own functions which it performs; in the process of its duty, it communicates with other cells which also help it in order to achieve common goals, which is maintenance of homeostasis within the cell.
Because they are made mostly or partly out of gas.
Is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect.