Fossils, or preserved parts of organisms from the distant past, have shown that species change over time. Radiometric dating can be used to determine the age of fossils by measuring the how much of the radioactive materials in each rock layer have broken down.
Functional groups are a group of molecules attached to a carbon-based core of an organic molecule. Key functional groups are 3. phosphates
Answer:
With millions of different kinds of organisms in the world, scientists must find order in all of this diversity. Scientists group living organisms into one or more of a few major categories as part discipline known as taxonomy. The bodies of organisms are organized into functional systems—cells are organized into tissues, and tissues are organized into organs. Body systems carry out critical functions, such as locomotion, reproduction, digestion, and circulation. All living things on Earth are composed of the same carbon-based, molecular building blocks.