Which characteristic is necessary for natural

selection to occur in a species?

(1) stability

(2) variation

(3) complex cellular organization

(4) a very low mutation rate

The plant adaptations described in the paragraph above would be found in what biome on Earth?

which of the following is an energy releasing process? a. metabolism b. anabolism c. catabolic d. all the above

Opportunity cost is what must be?

The main reason we aren't using more wind mills is because they have been known to kill birds. A.) True B.) False

What best describes expiration?

1. Suppose that xylem were located only in the roots and stems of a plant. Would fluids in the xylem still move? Explain.

What activity will decrease body temperature? Sweating Exercising Adding clothing Shivering

Organisms with true radial symmetry A. tend to be highly mobile. B. do not have a distinct head region and tend to be sedentary or passive drifters. C. can be divided into two matching halves along only one plane. D.

1. The Earth's carbon cycle consists of the flow, cycling, and recycling of all of the carbon on the Earth. Every living organism's composition includes the element carbon. How does carbon become part of living organisms?

Which of these is used to find the precise age of a rock? Index fossils Radioactive dating Relative dating Stratified rock layers