Dolphins have the same arm structure as wolves. What type of evidence for evolution does this represent? A. DNA
B. vestigial structures
C. homologous structures
D. embryology

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Adepositional also feature that forms where a stream enters a lake or an ocean is a