Bacteria and Other Multicellular Animals
Animals are multicellular, eukaryotic organisms that constitute the Kingdom Animalia. With few exceptions, all animals breathe air, secrete oxygen, can move, reproduce sexually, can move from a shallow body of water, through the umbilical cord to an adult human, and consume food. Primates and amphibians have nerves and a digestive tract, and all vertebrates are warm-blooded unless they have evolved special abilities to protect themselves from cold or heat.
The term animal is most commonly used to refer to any vertebrate animal with a nervous system and a specific set of body parts (the appendages and sensory organs). There are about 800 different classifications of animals, the most common classes being Prototheria, which includes sharks and rays; Arachnida, which includes dogs, cats, horses, rats, and porpoises; Metatheria, which includes horses, donkeys, llamas, hippos, sharks, turtles, and some birds; Eutheria, which includes all fishes, molluscs, snails, spiders, crustaceans, and unicellular organisms; and amphibians, such as salamanders and tadpoles. In addition, there are taxonomic classifications based on how an animal’s body forms and functions (e.g., chordate, chordless, rill, and plastron). The classification of an animal’s body structure (or anatomy) is also based on the types of cells it makes up: primary cells (which form organs and tissues); secondary cells (which form various parts of the body); and immune cells (which defend the body against external organisms).
The ancestors of today’s mammals evolved in the Paleocene era of earth history. These animals had no sense of right or wrong, and lived only for a few million years or so. During this early period of animal evolution, mammals had evolved into two separate groups-the Multituberculata and the Prototheria. The Multituberculata are characterized by a long neck, small canine teeth, short forearms, a head with a thick skull base, and ear bones. Multituberculates have evolved into four separate subspecies, and their fossils are found in various locations of the world.
The Prototheria have a very large body size and lived during the Mesozoic era. They are represented by a number of modern day rodents, including mice, rats, voles, hamsters, gerbils, chinchillas, and parrots. The most diverse specie within the Prototheria kingdom are the azhids, which are characterized by their bulbous eyes, long body styles, and elongated limbs. The most distinct specie within this kingdom are the eusocial insects. These organisms are characterized by several reproductive stages, which occur throughout the year in a semi-ecological system. The social insects belong to the Orthoptera Order and live either together or independently.
The bacteria that make up the Microbiome is the part of an animal’s immune system that fights against pathogenic bacteria. The majority of bacteria within the kingdom belong to the Order Protista, the same as the animals we know. Within the animal kingdom there are three main categories of bacteria-the prokaryotes, the eukaryotes, and the methanogens. Among the methanogens are bacteria that are commonly known as green leafy vegetables. The eukaryotes are comprised of all types of multicellular organisms and also include the protozoa and the echinophytes.
All animal cells are composed of membranes, but the proteins are held in place by a network of interrelated proteins. These proteins are called myofibrils. Myofibrils are a type of network, or net, that carry a great amount of information from one point to another. This information is carried on the protein surface of the membranes, called a cell membrane. The animal membrane is similar to a computer circuit board that allows cells to communicate with one another and control many of the vital functions of an animal’s body.