[Solved] The ________ is the central node that coordinates the flow of data by sending messages directly between the sender and receiver nodes. A)client B)server C)switch D)gateway Phenotype: The set of observable characteristics or traits of an organism resulting from the interaction of its genotype with the environment. Microscopic Characteristics: Features or properties of organisms or substances that are too small to be seen with the naked eye and require a microscope to be observed. Widow's Peak: A V-shaped point on the human forehead hairline due to a specific genetic trait. Straight Hairline: A form of hairline where the hair grows in a straight line across the forehead.