Gas exchange in animals occurs in the lung cells where oxygen moves from high to low concentration. What part of the cell is responsible for the process of gas exchange? *

Cell membrane

Nucleus

Cell wall

Ribosomes

How many different forms of vitamin a are active in the body?

The kinds of ribonucleic acid present in any plant cell will be [A] 2[B] 4[C] 3[D] 5

Are autotroph abiotic?

Why does a skydiver accelerate as she falls to the earth before opening her chute? A) because she loses mass during her travel B) because she gets further from the airplane C) because the force of the earth pulls on her D) because fewer forces are

Viruses are not considered to be living things, but they depend upon living cells for energy, reproduction, and protection at the expense of the cells that they invade.

Two parts of the alimentary canal where amylase is secreted

What does a ripened ovary develop into in a flowering plant?

What is the effect of sickle-cell anemia? a. Blocked respiratory pathways. b. Decreased neurological functions. c. Inefficient oxygen transportation. d. Susceptibility to contracting malaria.

You are exercising on a hot day your body temperature goes up. You begin to sweat. The sweat cools your body. The rise in your body temperature that signals start sweating is an example of: input. Output. Feedback. Process.

Arteriole blood pressure increases in response to all but which of the following? A. increasing stroke volume B. falling blood volume C. rising blood volume D. increasing heart rate E. all of these