How do desert plant parts (internal and external structures) help them survive in some places better than others? Utah Science with Engineering Education Standards: Strand 4.1: ORGANISMS FUNCTIONING IN THEIR ENVIRONMENT. Through the study of organisms, inferences can be made about environments both past and present. Plants and animals have both internal and external structures that serve various functions for growth, survival, behavior, and reproduction. Standard 4.1.1 Construct an explanation from evidence that plants and animals have internal and external structures that function to support