You are telling your friend that organic molecules are all made up of carbon backbones with hydrogens. she doesn't understand how there can be so many different organic molecules if they all are made up of the same basic components. you explain that organic

 They possess different functional groups.

Explanation:

Organic compounds are molecules composed of many carbon atoms bound together and in turn bound to hydrogen atoms. These molecules form the lipids, proteins, carbohydrates and nucleic acids that constitute all living beings. The reason why there is so much variety of organic molecules is because each one can have one or several functional groups in different positions, which gives them unique properties.

So a functional group is a group of atoms linked in a certain way, which present a specific physical-chemical structure and properties that characterise the organic compounds that contain them.

Examples are:

cancer   is   essentially   uncontrolled   mitosis   of specialized cells

children tend to take more after their grandparents more than their parents. it’s the dna you received that was passed down to you somewhere in your family. maybe one of your grandparents had/has straight hair and you might have gotten it from them.