During the earliest stages of the universe, the only things that existed were a) the sun and the planets. b) helium and hydrogen. c) clumps and gravity. d) stars.

the answer is "a.) well–developed vascular system."

explanation:

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

the answer would be   10%