Cholesterol is an example of a lipid.
I believe its called mitosis. Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Hope this helps:)
Answer : The type of reaction described in the sentence is Synthesis or Combination
Explanation :
The balanced equation for the reaction between Phosphorous and Oxygen gas can be written as

From the above equation we can see that there are two different reactants ( P and O₂ ) which are combining with each other to give a single product.
This type of reaction is known as Combination or Synthesis.
A general form of Synthesis reaction is given below.

Here we can conclude that a synthesis / combination reaction is the one where 2 or more reactants combine together to give only one product .
Weathering and chemical substance weathering
The Biotic Factor. (If that's what you were asking.)