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.
The right answer is Ribosomes
The ribosome is a complex composed of RNA and ribosomal proteins, associated with a membrane (in the granular endoplasmic reticulum) or free in the cytoplasm. Common to all cells (prokaryotes and eukaryotes), the ribosome (and especially its composition) varies according to the organisms, even if it is always composed of two distinct subunits.
The ribosome is a huge ribonucleoprotein complex that allows the translation of mRNAs into proteins.
The answer is Carbon Dioxide
Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs. ... These proteins provide structure and support for cells. On a larger scale, they also allow the body to move.
Chloroplast, sorry I'm a little late