Final answer:
The characteristics that differentiate subsurface colonies from surface colonies on an agar plate relate to the field of microbiology, specifically to colony morphology, and are not related to the techniques mentioned in the options. Colony morphology is characterized by the observation of a colony's size, shape, margin, elevation, texture, transparency, and color.
Step-by-step explanation:
The question pertains to the characteristics that differentiate subsurface colonies growing within the agar from those growing on the surface of the agar, which relates to the field of microbiology, and more specifically, to colony morphology. Colony morphology includes the examination of physical characteristics such as texture, transparency, color, and form of bacterial colonies, often observed in a lab setting when identifying and characterizing different bacterial species.
Small and oblong colonies that grow within the agar (subsurface colonies), as opposed to larger colonies that appear on the agar's surface, are indicative of differing bacterial behaviors, oxygen requirements, and possibly nutrient needs. While the initial question mentions various laboratory techniques such as the aseptic technique and the streak plate method, it is the colony morphology that is characterized by the observed physical differences between colonies. Utilizing the streak plate technique can lead to the separation of mixed bacterial cultures into individual colonies that can be further subcultured into pure cultures. This enables the precise description of colony morphology by analyzing a colony's size, shape, margin, and elevation.