A species is a group of organisms which can interbreed to produce fertile offspring
Organisms such as bacteria reproduce asexually.
Asxual reproduction is where an organism reproduces by making a copy of itself.
There is no interbreeding so they do not fit the definition of a species.
If you interbreed a male from one species with a female of another species you'll get a hybrid.
DIFFICULT TO CLASSIFY AS THEY ARE USUALLY INFERTILE- not a new species.
Organisms change and evolve overtime- this means the way that they are classified may also have to change.
Sometimes the organism may change that much a new species will form (difficult to tell when this happens.)
Gives everything a two part name
Two part latin name made form the genus and the species
Homo- sapiens (human)
Scientists all over the world use the same name due to the Binomical system therefore there is no confusion.
Recent common ancestors
Closely related in evolutionary terms.
Often look very alike and tend to live in similar habitats.
Not always the case- may look very different due to adaptation as they live in different habitats (camels and llamas.)