What is a gene? A) the different forms of a trait
B) a segment of DNA that is the basic unit of heredity
C) the appearance or characteristics that are seen in an organism
D) an organism's allele combination

Most of the fossils found in virginia are in the coastal plain, valley, ridge, and appalachian plateau regions, best suggesting that these geographic provinces a) were once covered by seawater. b) are the oldest parts of virginia. c) have a great deal of karst topography. d) have large amounts of sedimentary rock.

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which label identifies the part of the atp molecule that changes when energy is released in the cells of all living things