Katie wants to make ball-and-stick models of the four macromolecules. she has colored balls for each of the elements in these molecules, including the following. red: hydrogen black: carbon purple: oxygen green: nitrogen in which macromolecule will she use the black, red, and purple balls in a ratio of 1: 2: 1?

Which describes a difference between cephalopods and gastropods? cephalopods have a water vascular system, and gastropods have an open circulatory system. cephalopods live only in ocean environments, and gastropods live in a variety of environments. cephalopods have a simple nervous system, and gastropods have a complex nervous system. cephalopods are the largest group of mollusks, and gastropods are the smallest group of mollusks.