Answer:
carbon, hydrogen, nitrogen and oxygen
Explanation:
mostly, combination of carboxylic and amine groups
What are the questions that go with the model?
The answer is D. The natural selection is a theory which illustrates the gradual process of evolution in the population due to the change of environment. The key point is the mutation (variation) exists in the population before the environment changing. For C, if the environment does not change, though the adaptation is useful to environment, it will not be selected. Because the organisms without the adaptation will not die.
Answer:
A unicellular organism is formed by a single cell. ... The circulation in unicellular organisms is carried out by the movement of the cytoplasm of the cell called cyclosis.
