An article about organism diversity.
Diversity of Organisms
Biology is the study of living things. The work comes from a Greek word, bios, meaning ‘life’. It is easy to identify distinguish a living thing from a non-living thing.
For example, a living thing can grow and a non-living thing cannot.
All living things are divided into kingdoms. Two of these are the animal kingdom and the plant kingdom. Kingdoms are then divided into phyla (singular phylum).
There are millions of different species of plants and animals and new species are being discovered all of the time. Rather than try and study each one separately, it is sensible to put them together and study them as groups.
For example, if we consider the animal kingdom, we can divide all animals into two major groups: animals with backbones and animals without backbones. Animals with backbones are called vertebrates and animals without backbones are called invertebrates.
We can divide vertebrates further according to whether the animal has a body temperature the same as its surroundings (called cold blooded) or whether the animal is able to keep its body temperature the same even on hot or cold days (called warm blooded).
Cold-blooded animals cannot use internal processes to control their body temperature. However, a snake can warm up its body by basking in the sun. Such animals as fish amphibians and reptiles are cold-blooded whereas birds and mammals are warm blooded.
Each of these classes have their own characteristics. Fish generally have paired fins and gills. Amphibians have slimy skin, and spend some of their lives in water. Reptiles have dry scaly skin and lay eggs on land. Birds have feathers and also lay eggs on land. Finally, mammals have hair, and provide milk for the young from special glands.