4. All cells of an organism are engaged in many different chemical reactions. This fact is best supported by the
presence in each cell of thousands of different kinds of
(1) enzymes
(3) chloroplasts
(2) nuclei
(4) organelles

is this a question? wassup

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.

answercells,tissues,organs,organ,system-organism;

levels of biological organization; organism,population,community,ecosystem,biome,biosphere,

hope this .good luck