Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand and bacteria on the other hand.
In biological terms, species is the basic taxonomical rank. It can be defined as a group of similar organisms that are capable of interbreeding under natural conditions to produce fertile offsprings.
Therefore, a group of similar individuals that are respectively isolated form a species.
Species can also be defined as group of individuals that share the same gene pool.