Severe acute respiratory syndrome (SARS) is an illness caused by a coronavirus. Symptoms including high fever, headaches, and body aches typically occur 24 – 72 hours after infection by the virus. SARS is more serious in elderly patients. This information suggests that the reproductive cycle of the SARS virus is —

the correct answer is:

a population changes in response to a change in the environment.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.