Animals make up the bulk of the human population. There are some 5 billion earth-worms and one hundred ninety-five million fish that make up the human population as well. Virtually all animals live in a variety of environments ranging from the caves of the Andes to the ocean's depths. Some animals have evolved specifically to serve human purposes such as dogs to hunt or snakes to hunt prey. Other animals may be trained to assist humans in their day to day lives such as horses used for transportation. A variety of animals provide humans with a variety of necessary services including hunting, fishing, protecting wildlife, and farming.
All animals have a spongy interior covering called a plastron. Inside the plastron is the mesoplast, an area where cells can multiply to form both tissues and fibers. The blastula is the term used to describe the tissue contained within the mesoplast. Multicellular animals such as insects have their own small-sized plastrons inside the uterus and multiple copies of the material may be produced per cell. The sponges of these animals have two layers; the inner layer having the spongy material and the outer layer having a mesoplast similar to our own.
The Blastula contains a network of tubules or pockets called myofilaments, which are surrounded by an extracellular matrix, a sticky protein coat. The interior of the plastron of multicellular organisms is covered with a jelly-like fluid. All animals that make up the kingdom Animalia have a very simple digestive tract, similar to our own. The tubules contain a variety of cell types that are needed by the body for growth and development including, muscle cells, skeletal cells, pigment epithelium (a protective coating that covers the cellular membrane), specialized hormones and enzymes.
The blastula is a multicellular organism but in higher animals, a single cell can be found inside the plastron of the body. This cell belongs to the prokaryotic kingdom Animalia and is found in the stomach, small intestine and vagina. The sponge-like material inside the sponges is made up of a combination of both protein and nonprotein molecules. The proteins and nonprotein molecules are held together by the strong adhesive called collagen. The blastula is made up of billions of these cells, which are located in the uterine wall of all the different species of mammals.
Some animals that belong to the Lamarckian kingdom include amphibians and reptiles such as lizards, salamanders and geckos. The name for the multicellular leporine animals previously mentioned are actually a suborder of lizards. They do however differ in regards to the arrangement of the limbs and the body plan. The two types of animals that are classified as Lamarckia include those that have a tail and those that do not. All other kinds of animals belong to the Kingdom Prototheria which includes such animals as crustaceans and fishes. A type of carnivore, this group of animals has evolved on earth since the earliest days of the planet.
The Lamarckian order has four primary sub kingdom animals, which are defined as having animals that do not have exoskeletons (the ones that are under the skin); have chloroplasts (those that contain chlorophyll), are unicellular in nature and do not form multicellular organisms. In fact, these animals are quite different from modern multicellular organisms. One of the first kinds of animals to evolve on earth were the unicellular animals. They were very different in their anatomy compared to the multicellular organisms. The earliest fossils we know of in this order are dated at around two hundred million years ago. These fossils are in fact the first multicellular organisms to appear on earth.
Another group of animals that evolved on earth are the vertebrates or animals with backbones. The first vertebrates appeared around three hundred million years ago. Most modern vertebrates are lizards and snakes. The order of animals including insects is known as the Prototheria and it includes such amazing creatures as butterflies, dragonflies and some winged bugs. It is comprised of around five hundred different kinds of insects.
The class of animals that are commonly referred to as amphibians includes those that have both gills and live in water. They are generally considered to be a separate class from the invertebrates because they do not have an oral cavity and are capable of both respiration and breeding underwater. The order of animals or amphibians also includes a certain class of marine reptiles, which are classified as terrestrial animals and must feed on fish, plants and other aquatic animals. The other class of animals such as the cephalopods, cormorants, snails, and squids are considered to be terrestrial and can also feed on fish and sometimes even land-based animals.
