homeostasis
the condition in which an organism's internal eviroment is kept stable in spite of external change
adaptation
an inherited behaviour or physical characteristic that helps an organism survive and reproduce in its environment.
vertabrate
the bones that makes up the backbone of an organism. In humans, the 26 bones that make up the backbone.
invertabrate
an animal without a backbone
tissue
a group of similar cells that perform a specific function.
organ
a body structure that is composed of different kinds of tissues that work together
radial symmetry
a body plan in which any number of imaginary lines that all pass through a central point divide the animal into two mirror images
bilateral symmetry
a body plan in which a single imaginary line divides the body into left and right sides that are mirror images of each other
cnidarian
a radically symmetrical invertebrate that uses stinging cells to capture food and defend itself.
Mollusk
an invertebrate with a soft, unsegmented body; most are protected by a hard outer shell.
arthropod
an invertebrate that has an external skeleton, a segmented body, and jointed appendages.
exoskeleton
external skeleton; a tough, waterproof outer covering that protects, supports, and helps prevent evaporation of water from the body of many invertebrates
endoskeleton
an internal skeleton; structural support system within the body of an animal
chordate
an animal that has a notochord, a nerve chord, and throat pouches at some point in his life
notochord
a flexible rod that supports a chordates back just below the nerve chord
ectotherm
an animal whose body temperature is determined by the temperature of its enviroment's
endotherm
an animal who's body temperature is regulated by the internal heat the animal produces
fish
a vertebrate who's body temperature is determined by the temperature of it's environment, and that lives in the water and has fins.
cartilage
A connective tissue that is more flexible that, bone and that protects the ends of a bone and keeps them from rubbing together
amphibian
a vertebrate who's body temperature is determined by the temperature of its environment and that is lives its early life in water and its adult life on land
reptile
a vertebrate that is an ectotherm and has lungs and scaly skin and lays eggs on land.
bird
an endotherm vertebrate that lays eggs, has feathers, and a 4 chambered heart.
mammal
an endotherm vertebrate that has skin covered in hair or fur and glands that produce milk to feed young
mammary gland
an organ in female mammals produces mil for the mammals young
montreme
a mammal that lays eggs
marsupial
a mammal who's young are born at an early stage of development ad which usually continue to develop in a pouch on the mothers body
placental mammal
a marsupial that develops inside their mothers body until its body systems can function independently
placenta
an organ in most pregnant mammals, including humans that links the mother and the developing embryo and allows for the passage of materials between them.