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):
In humans and most animals (and more primitive plants), sperm cells are very much like tiny flagellates; again, humans have the genes to produce such forms. Of the protozoans that have both animal and plant characteristics, most are flagellates - there are entire subgroups of flagellates that are considered algae.