It's actually pretty easy to estimate the first number - all you have to know is the apparent angular size of the sun and moon in the sky (about half a degree each) and the the time it takes the moon to orbit the earth (about one month).
Eukaryotic Organelles. 1  Nucleus-a membrane bound structure that contains the cell's hereditary (DNA) information and controls the cell's growth and reproduction. 2  It is commonly the most prominent organelle in the cell.
The Cell Membrane is a Fluid Mosaic. A cell is the basic unit of life, and all organisms are made up of one or many cells. One of the things that all cells have in common is a cell membrane. It is a barrier that separates a cell from its surrounding environment.This outer boundary of the cell is also called the plasma membrane. cell is the basic unit of life, and all organisms are made up of one or many cells. One of the things that all cells have in common is a cell membrane. It is a barrier that separates a cell from its surrounding environment. This outer boundary of the cell is also called the plasma membrane.