IB Biology Sub-topic B4.2 Notes

You have now learned about organism evolution and speciation, biodiversity, and habitat. However, each habitat has a great number of species that each contribute differently. The functional role of an organism, in its environment, is its niche. There are two types of niches you need to be aware of:

1. Ecological niche - the species habitat and all its interactions. This includes what it consumes, its interdependence with other species, the time of day it's active, where it lives, and where it feeds.
2. Fundamental niche - the full range of conditions under which species can survive and successfully reproduce. 

Note that two species with the same niche cannot coexist as they would compete with one another, leading to the exclusion of one. This topic will focus on the distribution of organisms primarily on their:

1. Requirement of oxygen
2. Nutrition methods
3. Adaptations to nutrition
4. Competition