Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how



species A group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce.
variation Any difference between individuals of the same species.
evolution change over time; the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth
fossil the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock
adaptation The evolution of features that make a group of organisms better suited to live and reproduce in their environment
scientific theory a well-tested explanation for a wide range of observations or experimental results
mechanism The natural process by which something takes place
natural selection The process by which organisms that are best adapted to their environment are most likely to survive and reproduce
competition The struggle between organisms to survive as they attempt to use the same limited resources in the same place at the same time
mutation Any change in the DNA of a gene or a chromosomes
expression the appearance in a phenotype of a characteristic or effect attributed to a particular gene
fitness How well an organism can survive and reproduce in its environment
sexual selection A type of natural selection that acts on an organism's ability to get the best possible mate
coevolution the process by which two species evolve in response to changes in each other over time
randomly without method or conscious decision; indiscriminately.
interactions the action between
fossil record All the fossils that have been discovered and what scientists have learned from them
embryo the young organism that develops from a zygote
homologous structures Structures that are similar in different species and that have been inherited from a common ancestor
extinct Term used to refer to a group of related organisms that has died out
protein Large organic molecule made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
transfer move to another group, occupation, or service