1. Make an observation.
2. Ask a question.
3. Form a hypothesis, or testable explanation.
4. Make a prediction based on the hypothesis.
5. Test the prediction.
I'm thinking it might be fossil evidence. Hope it helps!
Answer:( answer for number one) an essential nutrient for the production of amino acids, proteins, nucleic acids. ( number 2 ) for the growth, maintenance, and repair of all tissues and cells, and for the production of the genetic building blocks, DNA and RNA
