Biotic refers to the living part of an ecosystem, while the abiotic refers to the non-living part of the ecosystem. An ecosystem is the interaction between the biotic and abiotic factors #3: tundra, desert, aquatic, and forest (I forgot the last one) #4 tropical forest has hot, wet climate because they are located 23.5 degrees north and south of the equator which is relatively close allowing it to get highly concentrated sun rays along with low pressure
