[Solved] A surgical procedure in which a catheter is threaded into the coronary artery affected by atherosclerotic heart disease, and then the balloon at the tip of the catheter is inflated and deflated to expand the lumen of the artery, is A) PTCA. B) MIDCAB. C) CABG. D) TMR. Insects: Arthropods belonging to the class Insecta, characterized by a three-part body, compound eyes, one pair of antennae, and typically two pairs of wings. Keystone Species: Keystone species are species that have a disproportionately large effect on their community or ecosystem relative to their abundance, playing a critical role in maintaining the structure of an ecological community. Community: In ecology, a community is a group of interacting species living in the same area, sharing a common environment. Small Numbers: A numerical quantity categorized as being less than some arbitrary value, often context-specific.