Give example of different ways in which observation are used in scientific inquiry

What type of lipids are found in all biological membranes?

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.

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?