Why can oxygen diffuse across a cell membrane but a protien cannot?
a. oxygen is polar unlike proteins
b. proteins asre blocked by protien channels
c. proteins are smaller than oxygen
d. oxygen is smaller than proteins

Photosynthesis converts solar energy into what type of energy?

Control of the body is accomplished by which of the following body systems? nervous system and circulatory system endocrine and repertory system circulatory and respiratory systems nervous system and endocrine systems

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