The sun is the ultimate source of energy for virtually all organisms. Photosynthetic cells are able to use solar energy to synthesize energy-rich food molecules and to produce oxygen.

To use a light microscope to examine animal or plant cells. To make observations and draw scale diagrams of cells. Turn the coarse focus so that the stage is as close to the objective lens as ...

Cells therefore rely on so-called chaperone ... long stretches of similar amino acid sequences within their primary structure. These stretches have been conserved through evolution and are vital ...

We can see how circuits work, and represent them with some simple diagrams, using basic electrical components like these. You start with a cell, or combination of cells. These could be batteries ...