Which is true about autotrophs?

a. They are primary producers

b. They make their own food.

c. They are the base of the food chain.

d. All of the choices are true.

Why was Hurricane Katrina especially devastating to the city of New Orleans? A. The hurricane's storm surge caused severe flooding in the city. B. The hurricane's category 5 winds destroyed buildings. C.

A cell produces a protein that will be used by other cells. When it ejects the protein, has it performed egestion, secretion, or excretion

In photosynthesis co2 is reduced to produce glucose. what is the ultimate source of electrons

Suppose you discover a new organism. What would you expect to see if you studied it under a microscope?

Which of the following statements about cell-cycle regulation is correct? A. Cyclins are regulatory nucleotides in the cell cycle. B. Cyclin-Cdk complexes phosphorylate carbohydrates. C.

Which of the following would cause the earth to be pulled into the sun? A. The Sun loses its gravitational pull. B. The earth suddenly loses its inertia. C. Mercury and Venus speed up in their orbit. D.

The axons of myelinated neurons are imbedded in a protective covering of A. gray matter. B. nodes of Ranvier. C. synaptic knobs. D. Schwann cells

How many years less (on average) is the life expectancy for 65-year-old african americans than for 65-year-old european americans?

Which of the following organisms can perform alcoholic fermentation? (1) yeast, (2) humans, (3) bacteria. a. 1 and 2 b. 1 and 3 c. 1 only d. 1, 2, and 3

What lung is more efficient than a avian lung?