| A | B |
|---|
| homeostasis | keeping constant internal body conditions |
| vertebrate | an animal with a backbone |
| adaptation | structures and behaviors that allow animals to function |
| invertebrate | an animal without a backbone |
| radial symmetry | if many lines can be drawn through an object producing mirror images, like a wheel |
| bilateral symmetry | if one line can be drawn through an image, producing mirror images, like a fish |
| tissue | a group of similar cells that perorm a specific function, like muscle, bone or blood |
| organ | a group of tissues that function together, like heart, lungs or brain |
| cnidarian | simple invertebrates that have stinging cells and take food into a central body cavity. Example: jallyfish |
| mollusk | an invertebrate with soft, unsaegmented body, often protected by a hard shell. |
| arthropod | an invertebrate with an exoskeleton, jointed appendages and a segmented body |
| exoskeleton | the external skeleton that does not grow with the organism, and must be shed periodically.f an organism |
| endoskeleton | an interior skeleton that grows with the organism |
| echinoderm | an invertebrate with an endoskeleton and a system of fluid-filled tubes |
| chordate | an organism that has a notochord, a nerve cord and a throat pouch at some point in its life |
| notochord | a flexible rod that supports a chordate's back |
| ectotherm | an animal whose body temperature changes with the environment |
| endotherm | an animal who regulates its own body temperature |
| cartilage | a tissue more flexible than bone |
| amphibian | an ectothermic vertebrate that spends its early life in water and adult life on land |
| reptile | an ectothermic vertebrate that has scales and lungs, and lays eggs on land |
| mammary gland | an orgna that produces milk in mammals |
| mammal | an endothermic vertebrate that has skin covered in hair or fur, and a 4 chambered heart |
| monotreme | a mammal that lays eggs |
| marsupial | a mammal that develops its young in a pouch on its body |
| placenta | an organ in a mammal's body that covers a developing embryo and allows gas and nutrient exchange |
