Why are pioneer species usually autotrophs? A. Newly established ecosystems do not usually have pre-existing food sources.

B. Only autotrophs are large enough to survive.

C. Autotrophs are usually at the top of an ecosystem's food chain.

D. Only autotrophs can survive where water is scarce.

When a doctor suspects that a patient may have diabetes, she will often have the patient take a glucose challenge test. after the patient drinks a large amount of sugary solution, his blood is drawn and the circulating levels of glucose in the blood are determined. which of the following curves do you expect from a patient with diabetes? a. curve ab. curve bc. curve cd. normal curvee. none of the above