Opal is a unique gemstone that often displays a beautiful play-of-color. Opal exhibits all colors and both light and dark base colors that reflect a rainbow-like display of multiple colors when viewed from different angles (play-of-color). On Mohs' scale of hardness, opal ranks 5.5 to 6.5.
Most protozoa are animal-like (heterotrophic) because their carbon and energy must be obtained by eating or absorbing organic compounds originating from other living organisms. As eukaryotes they have several organelles, including at least one nucleus that contains most of the cell's deoxyribonucleic acid.Source(s):ost protozoa are animal-like (heterotrophic) because their carbon and energy must be obtained by eating or absorbing organic compounds originating from other living organisms. As eukaryotes they have several organelles, including at least one nucleus that contains most of the cell's deoxyribonucleic acid. Source(s):
Protozoa. formerly, the name of an animal phylum comprising a large, diverse assortment of microscopic or near-microscopic one-celled heterotrophic organisms (protozoans protozoan, informal term for the unicellular heterotrophs of the kingdom Protista.orphology. A protozoan may be a plastic organism (ameboid type), but changes in form are often restricted by the pellicle. A protective layer is often secreted outside the pellicle, although the pellicle itself may be strengthened by incorporation of minerals.