Human being, teeth doctors and tools
Answer:
Option C
Explanation:
Dr. Leland Hartwell used baker’s yeast, <em>Saccharomyces cerevisiae</em>, as a model system, which was a highly suitable model for cell cycle studies. He introduced the concept of Checkpoints where he said cells are arrested if damaged so that the cells repair system can work to correct such damages. Dr. Paul Nurse used a different type of yeast, <em>Schizosaccharomyces pombe</em>, a type of yeast distantly related to the baker's yeast as a model organism.
Sand and glass have different chemical formulas, so that means that the atoms are rearranged and this is a chemical reaction.
When cells communicate by the signaling process, one cell produces a signaling molecule that must be received by the signal receptor on or in the responding cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).