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):
The word protozoa (singular protozoon, or protozoan) was coined in 1818, by zoologist Georg August Goldfuss, as the Greek equivalent of the German Urthiere, meaning primitive, or original animals. Goldfuss erected Protozoa as a class containing what he believed to be the simplest animals.Originally, the group included not only microbes, but also some lower multicellular animals, such as rotifers, corals, sponges, jellyfish, bryozoa and polychaete worms.oldfuss erected Protozoa as a class containing what he believed to be the simplest animals. Originally, the group included not only microbes, but also some lower multicellular animals, such as rotifers, corals, sponges, jellyfish, bryozoa and polychaete worms.