Blood is moved through the vascular system by

A. valves in the wall of the blood vessels.

B. peristalsis caused by smooth muscle in the blood vessel walls.

C. pressure gradients created by the heart.

D. osmotic pressure.

E viscosity of the blood

Which of the following is a reason for DNA replication in skin cells? O to produce identical daughter skin cells O to enable the skin cells to make more proteins O to allow the skin cells to adapt to a changing environment O to ensure daughter skin

Red blood cellsPlateletsWhite blood cells carry oxygen to cells and take carbon dioxide away.

Members of which genus of algae are found in ponds and have chloroplasts that are arranged in a spiral?

How do animals obtain food?

Whales and hippos are thought to have evolved from a common ancestor around 54 million years ago. Which of the following is also true about these species? A. Whales and hippos are physically identical. B.

Which area shows the climax community of secondary succession?

What type of dragon is the submeripper

Does glucose follow the same path as blood in the kidneys

Explain how to predict y-values using the equation of a regression line.

What non-renewable resource, when burned, is the leading cause of increased levels of carbon dioxide in the atmosphere?