Why do living things need enzymes? & What are two things that affect Enzyme function?

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

Read the following statements that describe how information flows in the nervous system. what is the correct order in which they occur? 1) response is carried to glands or muscles. 2) information is gathered. 3) information is processed and a response is formed.

Earth is tilted on its axis. which of these would not exist if earth had no tilt?