1- a of dna consists of a sugar, a phosphate, and a nitrogen containing base. 2- a is a change in the base sequence of a dna molecule.

What have we learned from fossil evidence about evolution? a) it is an abrupt change. b)the process is observable. c) it takes place during one lifetime only. d)the most complex traits are always selected.

Why is excretion necessary to maintain homeostasis?

Which equation is used to calculate the magnetic force on a charge moving in a magnetic field