15. The speed-time graphs below represent the motion of a car. Which graph represents a car that is moving at a constant speed but not
stopped? *
F
G
H
Med
E
F
H

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

What are the doorways into and out of cells, attached to the membrane, and built in the rough er.

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.