Nucleus
Cell
Identity what is represented by each letter.

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?

Match the following terms and definitions. the transformation of a larva to an adult; occurs only in animals having great differences in form between the larva and adult pupa 2. type of mammal that lays eggs monotreme nymph the part of certain insect life cycles in which the young animal has no wings or reproductive organs the developmental stage between larva and adult in insects undergoing metamorphosis metamorphosis 5. the male gonad which produces sperm testes

How do light years astronomers to determine the ages of distant objects in space ?