Data

Copy and paste the text below. It is read-only. Select All

T The skeletons of all vertebrate embryos are made up of cartilage but are usually replaced by bone as they grow T Warm-blooded animals warm their bodies by capturing the heat released by chemical reactions in their cells F Cold-blooded animals only live in cold places F Gills allow organisms to breathe in the water as well as on land Cartilage A flexible tissue that gives support and protection but is not rigid like bone Endotherms Animals that maintain a constant body temperature despite changes in the environment Internal The fertilization of eggs by sperm in side the female's body Ectotherms Animals whose body temperatures change with the environment. External The fertilization of eggs by sperm outside of the female's body