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.
no because Separation of oxygenated and deoxygenated blood in the heart of three types of animals. The three-chambered frog heart mixes oxygenated and deoxygenated blood in the ventricle. Therefore, the body never receives fully oxygen-rich blood.
Using little tweezers you can pull each strand
I think its C. global warming
because the other one directly threats aquatic bio diversity while global warming doesn't just affect aquatic biodiversity
A marine layer is an air mass which develops over the surface of a large body of water such as the ocean or large lake in the presence of a temperature inversion. ... As it cools, the surface air becomes denser than the warmer air above it, and thus becomes trapped below it.