5. Are all cells within an organism the same? If so, How can they differ?

Not all cells in an organism are the same. Some cells can be prokaryotic, some can be eukaryotic, some can be unicellular, and some can be multicellular.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.