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Science A2 Vocabulary
Terms and definitions for Chapter A2
the main bone, made up of many small bones joined together, that runs along the middle of the back in some animals
a hard outer covering that supports and protects some animals without backbones
to shed an animal's outer covering
organs for breathing found in fish and amphibians
one of a large group of animals with backbones that live part of their lives in water and part on land
an animal with a backbone that has dry, scaly skin
an animal with a backbone that usually has hair on its body and feeds milk to its young
a simple, automatic behavior
the cause of a behavior
a behavior caused by a stimulus