Final answer:
The realized niche of an organism refers to the habitat and resources it actually uses within nature as it interacts with other species and the environment, which is option (c).
Step-by-step explanation:
The realized niche of an organism is the range of areas and resources an organism actually uses within its environment as it faces competition and other ecological interactions. Two different species cannot occupy the same niche in the same place for an extended period of time, according to the competitive exclusion principle. Instead, each species occupies a unique niche to minimize competition and maximize survival.
A niche includes an organism's role in the flow of energy through the ecosystem, such as what it eats and what eats it, its interactions with other organisms, and its role in recycling nutrients. The habitat, as another fundamental aspect of a species' ecological niche, refers to the natural environment to which a species is adapted, encompassing both biotic and abiotic factors.
Therefore, the correct statement about the realized niche of an organism would be (c) The habitat that exists in nature as opposed to the ideal.