Answer:
Determining a substance's physical or chemical identity. What are the two main requirements for identification? The adoption of testing procedures that give characteristic results for specific standard materials and the number and type of tests needed to identify a substance to exclude all other substances.
C.Adenine and guanine<span> are </span><span>purines in DNA.</span>
Answer (A) I believe.. Good luck! ^-^
Answer:
Genes play an important role in determining physical traits — how we look —and lots of other stuff about us. They carry information that makes you who you are and what you look like: curly or straight hair, long or short legs, even how you might smile or laugh. Many of these things are passed from one generation to the next in a family by genes. Most cells have one nucleus. The nucleus is a small egg-shaped structure inside the cell which acts like the brain of the cell. It tells every part of the cell what to do. It contains our chromosomes and genes. Chromosomes come in matching sets of pairs and there are hundreds (sometimes thousands) of genes in just one chromosome. The chromosomes and genes are made of DNA.