the theory that states that the universe formed by rapid expansion of matter and energy from an initial infinitely small, dense point

A fundamental substance that cannot be broken down by chemical means. Examples include sulfur, copper, gold, and silver.

a group of interbreeding organisms that can produce fertile offspring

organisms made of one or more cells that have a membrane-bound nucleus and membrane-bound organelles

the process by which inherited characteristics within a population change over generations

structures that occur in different species but are similar enough to suggest that the species had a common ancestor

organisms that usually are made of a single cell and do not have a membrane-bound nucleus or membrane-bound organelles

remains or traces of organisms preserved over long periods of time

An organizational chart that chronologically divides the natural history of earth into eras and periods

a type of cell without a membrane-bound nucleus and without membrane-bound organelles, considered by scientists to be a more primitive type of cell than the more complex eukaryotic cells

the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do

the process of breeding organisms with the most desirable traits

structures that appear to have no function for the organism but probably had a function in an ancestral organism

origin and formation of a new species