The process that results in the formation of different cell types occurring through selective changes in genetic activity that causes some genes to be turned off, while others are turned on is called .

A. fertilization
B. conception
C. development
D. differentiation

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

Where is having brightly colored feathers that attract mates most clearly an adaptation for a bird? a. a forest with dense vegetation b. a sandy beach beside an ocean c. a snowy tundra with little vegetation d. a swamp with many hawks that eat birds