Most cell signals are chemical in nature. For example, prokaryotic organisms have sensors that detect nutrients and help them navigate toward food sources. In multicellular organisms, growth ...

A solar cell is made of two types of semiconductors, called p-type and n-type silicon. The p-type silicon is produced by adding atoms—such as boron or gallium—that have one less electron in their ...

The process of meiosis happens in the male and female reproductive organs. As a cell divides to form gametes: ...

Microscopes are needed to study cells in detail. Cell division - AQA Chromosomes carry genetic information in a molecule called DNA. A type of cell division called mitosis ensures that when a cell ...