Genetic engineering, for one. So is Darwinism.
A complete medical history, physical, neurological exam, electrical tests, blood and urine tests, challenge tests and genetic tests.
The Ice/Salt challenge The saltine challenge The cinnamon challenge The banana and sprite challenge The chili pepper challenge The gallon challenge
To rise to the challenge is to accept the challenge
To 'brook no challenge' means there is no challenge that you will turn away from.
What makes a challenge a challenge is to attempt something you're not sure you can do. A challenge is something that is a difficult task but you are trying to see if you can do it. For example, a spelling bee can be a challenge.
Genetic Conversation Genetic Conversation
Genetic Conversation Genetic Conversation
A genetic error is an genetic disease
Genetic drift
Running in the New York City Marathon was a (challenge) that Nina felt ready to overcome.
The cinnamon challenge, banana and Sprite challenge, the saltine cracker challenge, the jello challenge.