Hormones can be divided into three classes. lipid-derived, amino acid-derived, and peptide (peptide and proteins) hormones. Cholesterol is a fat and fats are lipids. They fall into the protein and lipid category.
Activation energy ........
A unicellular protist is a eukaryotic cell because it has a nucleus enclosed by a membrane. Protist cannont be grouped with plants, animals or fungi. However they are still eukaryotic.
Stable elements are those which have atleast one isotope with no tendency to "decay", i.e., change into anotherelement.
