the science calorie (little c) is a measure of heat energy the food calorie (big C) is a measure of energy that we burn, but it is equal to 1,000 science calories so 1 big C is equal to 1,000 little c's.
Protists are a group made up of protozoa, unicellular algae, and slime molds. We will concentrate on the animal portion of this group: the protozoa (proto = first, zoa = animals).
Historically, protozoa were defined as single-celled organisms with animal-like behaviors, such as motility and predation. The group was regarded as the zoological counterpart to the  protophyta , which were considered to be plant-like, as they are capable of photosynthesis.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.