N the sierra nevada mountains of california there are many populations of the checkerspot butterfly euphydryas editha. you notice that females of one population lay their eggs near the tip of a plant's stem (population a). females of another population in the same area lay their eggs at the base of the stem on a different type of plant (population b). the young hatch out as caterpillars; they live on the host plant and eat its leaves.

Edith's checkerspot (Euphydryas editha) is a species of butterfly in the family Nymphalidae. It is a resident species of western North America and among the subspecies, entomologists have long been intrigued by their many phenotypic variations in coloration, wing length, and overall body size.[1] Most populations are monophagous and rely on plants including Plantago erecta and Orthocarpus densiflorus as its host species in developing from eggs through to larvae, pupae, and mature butterflies.[2] Males exhibit polygyny whereas females rarely mate more than once. Males devote most of their attention to mate acquisition, and such mate locating strategies such as hilltopping behavior has developed.[3] Climate change and habitat destruction has impacted certain subspecies. Two subspecies in particular, Euphydryas editha quino and Euphydryas editha bayensis, are currently under protection via the Endangered Species Act.[4]

Explanation:

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

maritime tropical may be your answer.