What structural feature allows lipids to insulate and waterproof an organism

People who exercise for an hour may have lower cholesterol levels. is that a statement? a law? or a hypothesis?

Hemoglobin is the compound in red blood cells that carries oxygen to the body. the distribution of hemoglobin in women in g/dl of blood is approximately normally distributed with mean 14 and standard deviation 1. too little hemoglobin, and you're anemic. 2. too much, and (unless you live at high altitudes), you can have other problems.

Me with these questions if you’re it sure don’t answer