How Do Animals Fit Into the Animal Kingdom?

All animals are essentially eukaryotic, with each of the cells of the body having a nucleic acid (DNA) containing genetic code within its nucleus. The genetic code is passed down by inheritance and is inherited by offspring. All living animals are born with a genetic blueprint that enables them to reproduce as fully developed animals. However, some animals may have a mutation that prevents them from reproducing normally. These animals can still grow to adulthood and reproduce, but at a much slower rate than normal.


Mammals and Porcupines are two examples of animals that have an autosome (sex) chromosome. The term ‘autosome’ is used to indicate a chromosome regardless of whether it is asex or a non-sex chromosome. Some mammals, such as humans and all mammals, have only a single sex chromosome and these are referred to as ‘monosomes’. In other animals, the chromosome may be used and some possess both asex and non-sex chromosomes.

An eon is a reproductive organism that is capable of living for millions of years. The word ‘eon’ derives from the Greek words eon (anither) and demos (males). The word ‘species’ is used to designate a group of organisms that are descended from a common ancestor. This definition excludes all species that are considered to be derived from more than one species. Therefore, all animals on Earth are classified based on how closely they are related to other species.

The classifications of animals can also be based on how closely related they are to other animals. Synonymy is a case in which animals share characteristics of one another but are very different in appearance. A polypeptide is a protein that is made up of chains of amino acids. Every living cell contains these chains and these play an important role in how the cells function.

amphibians have split from the mammal kingdom after evolving millions of years ago. It is believed that these animals first appeared on earth through dinosaurs. The most famous among them are the dinosaurs and whales. Most amphibians live in fresh water and spend most of the day under the water. They have few teeth and have flexible jaw joint muscles to allow them to breathe underwater.

Eukaryotic organisms are eukaryotic in which cells are enclosed by an outer membrane and are therefore protected from outside effects. Examples of eukaryotic organisms are the mitochondria in plants and the plastids in algae. A unicellular organism is a unicellular organism that consists of numerous prokaryotic bacteria and eukarya. The most common example of a unicellular organism is bacteria.