Which kinds of cells are always single-celled?

Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. the chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. the chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production c. free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone select the best answer from the choices provided

How is mitosis different in plants and animals? a. in animals, the cell membrane pinches together. b. in plants,the dna is one circular chromosomes. c. in plants, there are no sister chromatids. d. in animals, a new cell wall forms.

What the theory that the sun goes around earth was replaced with the theory that earth goes around the sun this was an exaple of a