Veins have a much lower blood pressure than arteries. Which of these prevents backflow of blood in veins?

A. pressure applied by the heart

B. one-way valves in veins

C. thin muscular walls of veins

What is the main conflict described in this excerpt? Clover feels unhappy and is unsure about whether or not to rebel against Animal Farm. Clover experiences distress because her beliefs go against what Old Major taught her.

What were the first true terrestrial animals.?

What is the difference (in mV) between the membrane potential at rest versus the threshold potential in an axon?

Celiac disease affects the small intestine. The immune system attacks the gluten protein found in wheat, rye and barely, and also damages the lining of the small intestine. What is the primary function of the small intestine?

Give an explanation of why a population might have a clumped distribution in an area.

The outer periphery of the intervertebral disk is composed of strong fibrous tissue called the:

4. Which organism (s) are carnivores? 5. Which organism (s) are omnivores? 6. Which type of heterotroph is missing from this food web?

Coronary heart disease (chd) is the leading cause of death in the united states, true or false?

The nurse should educate the client prescribed a stimulant cathartic to be alert for which common adverse effect

A substance that produces insensitivity or stupor is called a