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.
Answer: Level of organization from electron to an organism is shown in the figure, have a look on it will help you a lot.
Answer: The water cycle, also known as the hydrologic cycle, describes the process of how water moves through Earth's environment. In general, water evaporates from oceans, then it condenses in the atmosphere as water vapor cools. When enough water gathers in clouds, it precipitates back to the Earth's surface as rain, hail, snow or sleet.
I think the correct answer is B
