What does a scientist need to determine the absolute age of rock A - relatives ages of the surrounding rocks
B- age of intrusion
C- distance from plate boundary
D- parent - daughter ratio of certain elements

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

What is the compliment dna strand to the following sequence: ttgactaggcta

Archaebacteria use for movement. celia flagella pili cell walls