Module 20 Lesson 1-2 Vocab

protist

protist

unicellular, multicellular, or colonial eukaryote whose cell wall may contain cellulose(plantlike, animal-like, or fungus like) lack complex organ systems and live in moist environments.

vertebrate

an animal has an endoskeleton and a backbone

invertebrate

animals without backbones

endoskeleton

internal skeleton (grows with you)

exoskeleton

hard or tough outer coverings that provide framework or support

internal fertilization

when the sperm and egg combine inside of the animal’s body

external fertilization

egg and sperm combine outside of the animal’s body

blastula

fluid filled BALL of cells formed by mitotic cell division of the embryo

gastrula

two cell layer SAC with an opening at one end

hermaphrodite

produces both egg and sperm in the same animal body

tissue

a group of cells that is specialized to perform a specific function

zygote

sperm penetrates the eggs to form a fertilized egg

ectoderm

Outside layer and that forms nervous tissue and skin

endoderm

Inner layer that forms digestive organs and lining of the digestive tract

mesoderm

Middle layer that forms the muscle tissue, circulatory system, excretory system, and in some respiratory system

phylogeny

evolutionary history of a species

anterior

head end

posterior

tail end

dorsal

backside

ventral

underside or belly

cephalization

tendency to concentrate nervous tissue and sensory organs at the anterior end of the animal

symmetry

similarity or balance among body structures

bilateral

the animal can be divided into mirror image halves among one plane through the central axis

radial

can be divided along any plane, through central axis, into roughly equal halves

protostome

the mouth develops from the first opening in the gastrula

deuterostome

the anus develops from the first opening in the gastrula(humans)

coelom

fluid-filled body cavity completely surrounded by the mesoderm(with)

acoelomate

animals that do not have a coelom(without)

pseudocoelom

fluid-filled body cavity that develops between the mesoderm and the endoderm(fake)

cartilage

flexible tough material that makes up the skeleton

notochord

flexible rod like structure that extends the length of the body

chordate

deuterostomes that have a dorsal tubular nerve cord, notochord, pharyngeal pouches, and postanal tail at some point in its development (humans)

dorsal tubular nerve chord

tube shaped chordate nerve cord located above the digestive organs

neural crest

group of cells that develops from the nerve cord in vertebrates

postanal tail

used primarily for locomotion

pharyngeal pouches

paired structure connecting the muscular tube linking the mouth cavity and the esophagus