A type of fish without jaws or paired find

People who exercise for an hour may have lower cholesterol levels. is that a statement? a law? or a hypothesis?

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?