Taxonomy, species and types of living things
A species is a group of more similar living organisms in the shape that can reproduce to give birth of new fertile individuals which are able to reproduce and keep the existence of the species.
The species is the basic classification unit for living organisms, Linnaeus used the species as a fundamental unit of the natural classifying system, African, European and Asian humans whatever their colour, race, or home are also belonging to one species (Human).
The taxonomy is a branch of biology that searches for similarities and differences among living organisms, and it places similar ones in groups according to a certain system in order to ease their study.
Intercourse may happen between some of the coupled species, but the product offspring is sterile.
For example, when there is intercourse occurring between a donkey and a horse, the product offspring will be a sterile female called a “Mule”, The intercourse between a zebra, and a donkey produces a sterile female called “Zonkey”.
If you look at the dogs, the cats, and the rabbits, You will notice that although the cats differ from each other, they differ more than the rabbits, and the dogs, So it is impossible for the cats to mate with the rabbits.
Mating can take place among any couple of cats whatever the difference in shape or size, so, all the cats are placed in one species, while the rabbits are classified in another different species and so dogs.