Biology: DNA as the "transforming principle"

How Griffith and later Avery, McCarty and MacLeod found strong evidence that DNA is the "transforming principle" that encodes genetic information.

Biology

Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course.

DNA discovery and structure

Today, we know that DNA is the genetic material: the molecule that bears genes, is passed from parents to children, and provides instructions for the growth and functioning of living organisms. But scientists didn’t always know this. In fact, for many years, researchers thought that protein would turn out to be the genetic material! Learn more about the properties of DNA and how it was identified as the hereditary molecule.

Topic: Science

Learn about all the sciences, from physics, chemistry and biology, to cosmology and astronomy, across hundreds of videos, articles and practice questions.