Which of the following is an organelle?
A. a brain
B. a cell
C. lungs
D. a nucleus

Why do you think the puppy litter was all dark-haired?

When an object is moving away from you while still making a sound, the pitch of the sound is perceived to a. lower b. unchanged c. fluctuating d.higher

which is an effect of short-term environmental changes? a) adaptation b) speciation c) extinction d) death (5 points)