The description of a cell organelle is given below.
• acts as the control center.
• give directions to make proteins.
• contains genetic material
what organelle is being described?
a) the nucleus
b) the chloroplast
c)the endoplasmic reticulum
d) the mitochondria

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 does human environment effect the biosphere

Where are the strongest jet streams located?