a form of chemical bond characterized by the sharing of a pair of valence electrons between atoms a group of atoms bonded together forming the smallest fundamental unit of a pure substance any physical or chemical imput that is sensed |
the shape of DNA that resembles a spiral staircaseor a twisted ladder |
cycle by which materials necessary for organisms are circulated through the environment (e.g. water, carbon, nitrogen) |
descent with modification of organisms from common ancestors |
velocity=displacement/time |