Eukaryotic cells have many different molecules which control the cell as it goes to the cell cycle. Select which of these would not be a valid reason for cells need to have these control molecules present

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

How do you date a sample of rock that you suspect as being one of the earliest on earth

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?