<u>Instructions provided by genetic material:</u>
Genes control everything from hair color to blood sugar by telling cells which proteins to make, how much, when, and where. Proteins are found in a wide variety of foods. Plus the human body is able to synthesise them. Unlike carbs and lipids, proteins are made according to instructions provided by our genetic material (DNA).
Also have nitrogen. Our bodies are able to break down the proteins in goods and utilise the nitrogen for many important processes. Carbs and lipids do not provide nitrogen.
Amino acids, lipids, and other carbohydrates can be converted to various intermediates of glycolysis and the citric acid cycle, allowing them to slip into the cellular respiration pathway through a multitude of side doors. As for protein, our bodies don't maintain official reserves for use as fuel. Rather, protein is used to build, maintain, and repair body tissues, as well as to synthesize important enzymes and hormones.
A is the answer. This is because this was not covered by the Twin studies.
Good luck!
-RxL
1, 2& 4th bullet I think is correct
