Document Type

Teacher Resource

Grade Level

Grade Level: 4th Grade

Publication Date



Plants and animals evolve to survive and reproduce in their environments. Both their internal and external structures will be well suited to support survival, growth, behavior and reproduction. All animals have a mouth. Its function is to take in food, without which it could not survive to reproduce. The type of mouth, however, will vary between animals, depending on what they have evolved to eat. Internal organs of the digestive system will likewise vary depending on an animal’s diet. All parts of the system for eating and digesting food must work together.



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