Which of these would not be a valid scientific theory?
a)all cells come from pre-existing cells.
b) humans originated on earth from outer space.
c) the universe is expanding at a constant rate.
d) at one time, all of earth's continents were one large land mass.

Plzzz hurry im being timed ! humans, like other organisms, require energy for growth and repair. when cells create atp for energy, carbon dioxide is produced as a waste product. how does the body respond to this process in order to maintain homeostasis? a. the digestive and respiratory systems interact to move carbon dioxide to the lower intestine, where it is transformed into methane. b. the circulatory and digestive systems interact to move carbon dioxide to the stomach, where it to break down food. c. the nervous and urinary systems interact to move carbon dioxide to the kidneys, where it is absorbed into the bloodstream. d. the circulatory and respiratory systems interact to transport carbon dioxide to the lungs, where it is expelled from the body.

Nitrofurantoin used during the fifth week of pregnancy places the neonate at risk for which condition?

Illustrate, label, and explain how atmospheric carbon and oxygen find there way into a consumer and then back into a producer. include the following terms in your illustration: co2, 02, respiration, photosynthesis, sugar, mitochondria, chloroplast, water, solar radiation