What does homogeneous and herogeneous mean?

What must happen before a body cell can begin mitotic cell division

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.