Beta-adrenergic blocking agents decrease the oxygen demands of the heart by what mechanism? a. increasing cardiac output, thereby increasing the oxygen supplied to the heartb. increasing blood pressure, which increases the amount of blood returned to the heartc. increasing conduction to the atrioventricular node, thereby increasing cardiac outputd. decreasing the heart rate, allowing for longer filling time and increased blood to the heart

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Abody cell has been growing and at synthesis proteins.in the nucleus of this body cell,dna replication is taking place. and a copy of the cells genetic material is copied.which of the following is the best conclusion you can make about the life cycle of this cell ? a) the cell is ready to undergo mitosis.and a chemical signal will send the cell to prophase b)the cell is undergoing meiosis and will cross over the genetic material next c)the cell is in the s phase of interphase and will move next to the g2 phase d) the cell is in the g2 phase of the interphase and is ready to begin diving