1. why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
2. what criteria do we use to decide whether something is alive?
3. what are outside raw materials used for by an organism?
4. what processes would you consider essential for maintaining life?

pls answer fast

1.   The oxygen requirements of an animal cannot be met by the process of     diffusion as diffusion is a very slow process. To overcome this, multicellular organisms have specialized cells and tissues for performing various necessary functions of the body such as intake of oxygen and food.

2.   What criteria do we use to decide whether something is alive? Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organism can also have movements, which are not visible to the naked eye.

3.   An organism uses outside raw materials mostly in the form of food and oxygen. The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment.

4.   The various processes essential for maintaining life are nutrition, respiration, transportation, excretion, control and coordination.

here it is hope it helps you out...

"The natural extinction rate" defines the background extinction

Explanation:

The background extinction rate which is being used for the evaluation of the rate by which the extinction in the earth's geological as well as the biological past took place before the contribution of the human beings as the primary contributors to the extinctions. Extinction happens when the last species of the plants or the animals dies out. This occurs as a result of the climate change or human activity.Background extinction occurs at a steady rate over geological time and is the result of normal evolutionary processes, with only a limited number of species in an ecosystem being affected at any one time.