Answer:
Cells are considered the basic units of life in part because they come in discrete and easily recognizable packages. That's because all cells are surrounded by a structure called the cell membrane — which, much like the walls of a house, serves as a clear boundary between the cell's internal and external environments.
I'm pretty sure that the main purpose of the U.S. Bill of Rights is to define the civil liberties of American citizens. It refers to the first 10 amendments of the U.S. Constitution. Also, it was introduced in 1789 to guarantee the protection of the basic rights that citizens continue to enjoy.
A test cross is used<span> to determine if a group exhibiting a dominant trait is homozygous or heterozygous for that trait.</span>
♥ A Light source is the white circle seen while looking through a microscope.
