Answer:
The biologist is studying about the ecological community.
Explanation:
The ecological community refers to the community in which population of different types of species survives together. As the biologist is observing about the interaction of different populations of Pennsylvania region, it can be inferred that the he is studying about the ecological community of Pennsylvania region.
The population surving in the community interact with each other through different modes of interaction. It may either parasitic, or mutual, or competitive or predication or commercialism.
Feces are deposited on the ground, and the bacteria in the soil breaks it down, and uses the nutrients
If the earth wasn't spinning , we wouldn't have summer, winter, fall, spring etc, it is important because we need the sun for certain seasons and no sun for others.
A because the dna paternity test is not genetically modified information that something that deals with correlation ppl and other animals
