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):
Other protozoans include the amoeba and the organisms that cause malaria and African sleeping sickness. Paramecia belong to a group of protists called protozoans, organisms that behave like animals. The paramecium, like other protozoans, must consume food to survive. Other protists, such as algae, can make their own food like plants. The slime molds are protists that exhibit behaviors similar to fungi.