Biology is the study of all aspects of life, from the smallest unit of DNA in a cell’s nucleus to the massive algal blooms on the ocean’s surface.
Scientists who study biology are called biologists. Since biology is a science, biologists use the scientific method, a specific set of steps designed to test answers to a problem, when they do their experiments.
Biology is a very broad science; some scientists claim that there are over fifty branches of biology – but there are five principles that unify all fields of modern biology.
1. Cells are the smallest unit of life.
Microbiologists study cells and other forms of life that are too small to be seen by the naked eye. Antonie van Leeuwenhoek was a biologist who improved the microscope, and enabled people to be able to see bacteria for the first time.
2. Units of heredity called genes are how traits are passed from generation to generation.
James Watson and Francis Crick’s discovery of the double helical structure of DNA in 1953 clarified our understanding of how and why we look like our parents.
3. Living things change over time, or evolve.
The most famous evolutionary biologist, Charles Darwin, coined the phrase “survival of the fittest,” and created a terrific controversy on the ancestry of humans.
4. In order for an organism to survive, it must regulate its body to keep its internal state constant.
First named by Claude Bernard, this principle, called homeostasis, is one of the most important concepts in medicine.
5. (Finally,) All living things require energy to survive. Whether it’s a tiny ant or a huge sequoia tree, it needs energy to grow and reproduce.
It’s a biologist’s job to discover how.