Why arteries have thick and elastic muscular walls?

What advantage does a crop that undergoes vegetative reproduction have over plants that start from the seed? 1points a they store nutrients. b they can travel farther. c they experience more genetic variation. d they only occur in high-resource environments.

The big bang theory suggest that the universe is about - 300 million years old - 4.6 billion years old - 30 billion years old - 13 billion years old

Internal feedback works to maintain homeostasis when your a. heart rate decreases as your white blood cells increase b. breathing rate decreases as your red blood cells decrease c. heart rate increases as your liver is cleaning blood d. breathing rate increases as your heart rate increases