Which one of the following molecules can MOST easily pass through the plasma membrane unassisted? A. Ca2+, a positive ion

B. Cl−, a negative ion

C. CO2, a nonpolar gas

D. glucose, a large sugar

The smaller and nonpolar molecules

pass through more easily.

So pick CO2.

you know that this symptom is misleading and quite often is related to: heart attack

a heart attack is a condition that occurs when the blood flow that transports oxygen to the heart muscle is damaged or cut off completely. the coronary arteries that supply the heart muscle with blood flow can be blocked by the accumulation of plaque. also, when the plaque within the heart artery breaks, it creates blood clot that can also hinder the blood flow. men that are over 45years of age and women that are over 55years of age are at risk of having a heart attack. the symptoms of a heart attack include chest discomfort, chest pain, coughing, and shortness of breath.