If many different species live in an ecosystem, this the ecosystem to fill its a. populations b. niches c. producers d. communities

Which of the following is not a defining characteristic of plants?

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.