birds		The earliest vertebrate that had legs positioned directly beneath its body.
skin		The specific environment in which an animal lives.
urine		Sharks, rays and skates are this kind of fish.
water		A fish's heart has ____ ____.
hole		What the word "amphibian" means.
turtle		Acts as protection for amphibians and also helps them sneak up on their prey.
bony		The bones that make up your backbone.
reptile		Most fish carry out ____ fertilization.
doublelife		Native to Louisiana, it is the largest living reptile.
fish		They have four legs, usually claws on their toes, external ears, movable eyelids and two lungs.
camouflage		Frogs and other amphibians are one of these.
gillslits		Each vertebra has one in it to allow for your spinal cord.
tadpole		The legs of frogs and toads have become adapted for this.
habitat		Ectothermic vertebrate that begins life in the water and spends adulthood on land.
endoskeleton		The larva of a frog.
lizards		An ectothermic vertebrate that has scaly skin and lungs.
vertebrae		An animal whose body temperature changes depending on the temperature of its environment.
kingcobra		The world's longest venomous snake.
twochambers		Has a shell, and internal membranes that help keep an embryo moist and allow it to carry out life functions.
kidney		Allows a fish to obtain oxygen from the water.
swimbladder		Watery fluid excreted from the kidneys that helps an animal conserve water.
snakes		Most scientists think they are a direct descendant of the dinosaurs.
biologicalindicator		Sometimes ectotherms are referred to as this.
ectotherm		All snakes are _____.
external		Internal skeleton made of bone and/or cartilage.
ventricle		Have no legs, no eyelids, no external ears and usually only one lung.
gills		Amphibians also exchange oxygen and carbon dioxide through this.
coldblooded		Organ that filters waste from the blood.
leaping		An animal that at some time in their lives will have a notochord, a nerve cord and gill slits.
amnioticegg		Chambers of the heart.
dinosaurs		Animal whose body regulates its own temperature by controlling the internal heat it produces.
atria		Most fish fall into this category.
cartilaginous		Allows bony fish to stay stable at different depths in the water.
alligator		You had some when you were an embryo, but not any more!
jawlessfish		Pumps blood out to the lungs and body.
chordate		An ectotherm that has fins and lives in water.
amphibian		Amphibians will return to this to reproduce.
endotherm		Reptile whose body is covered by a protective shell that includes the ribs and the backbone.
carnivores		There are only two species of them left on Earth.