Biodiversity – Classifications of the Animal Kingdom
All living things are made up of animal cells, which are made up of protein. Although most of us think of animal cells as being very small, there are actually a wide variety of animal sizes with their own unique characteristics. Not all animals are warm-blooded, some are cold blooded, and others are ectothermic (they need an external temperature source to regulate their body temperatures). In fact, it is estimated that approximately 99% of the animal kingdom is made up of some kind of animal cell.
Vegetables and plants are made up of multicellular organisms in the plant Kingdom. Plants are made up of a single cell, while animals are made up of multicellular organisms that are composed of many different cells. Animals breathe air, take oxygen to breathe, can reproduce sexually, and eat food. The cell walls of plants are very tightly packed while the cell walls of animals are loosely packed and have complex ribosome structures. As a result, animals secrete a compound to protect their body from infections, while plants release chemicals as defense.
Bacteria, archaea, protozoa, and viruses all belong to the Kingdom Protista, also known as the eukaryote Kingdom. The eukaryote Kingdom has about three hundred living organism species including all the plants and animals we are familiar with. About a hundred thousand viruses and bacteria are present in the human body and other animals, including humans. It is believed that animals shed an organ called a cell that protects them from invading organisms. However, the cells become infected and reproduce in a new location, which is what we call a virus.
One of the greatest mysteries of the animal kingdom is the origin of animals. Recent research is suggesting that dinosaurs became extinct not forty million years ago, but at least fifty million years ago. Some palaeontologists think they were wiped out by a massive asteroid. Evidence suggests they became multicellular eukaryotes like modern day lizards and fish.
Multicellular organisms have their roots in animal cells. Animal cells are made up of both prokaryotic and eukaryotic cells. The eukaryotic cells are very small and can be either animal or plant. They have ribosomes that contain almost all DNA necessary for the formation of all the animal species. It is possible that all of the animals on the planet started out living as multicellular organisms.
Some animals do not look like any of the animal kingdom animalia, such as sharks and whales. But these animals are actually classed as eusocial insects. Eusocial means living in a group of several animals. There are about one hundred different animal families and mammals that live together in a eusocial animal body plan.