Chapter 32: Animal Diversity Summary Flashcards
Groups of similar cells that act as functional unit
Tissues
Multicellular eukaryotes
Animals
A succession of cell division without growth between divisions
Cleavage
Cleavage lads to formation of a _________, often in the room of a hollow ball of cells
Blastula
The blastula undergoes ___________; forming a gastrula
Gastrulation
Formed during gastrulation with different layers of embryonic tissues
Gastrula
Is sexually immature and morphologically and behaviorally distinct from the adult stage
Larva
After this process, larvae become juvenile that resemble adults but are sexually immature
Metamorphosis
Unique family of regulatory genes of animals
Hox genes
Bilaterally symmetrical form
Bilaterians
Complete digestive tract
Bilaterians
Efficient digestive system with a mouth and anus at opposite ends
Bilaterians
Often sessile or planktonic (drifting or weakly swimming)
Radial symmetry
Lack symmetry
Sponges
Move actively and have a CNS
Bilateral animals
Body parts arranged around a single central axis
Radial symmetry
Imaginary slice through the central axis divides the animal into mirror images
Radial symmetry
Body parts are arranged around 2 axes of orientation (head-tail and dorsal-ventral)
Bilateral symmetry
Only 1 imaginary slice divides the animal into mirror image halves, right and left side
Bilateral symmetry
Covers the body’s surface
Ectoderm
Outer covering and CNS
Ectoderm
Innermost layer
Endoderm
Lines the archenteron
Endoderm
Blind pouch that will form the gut
Archenteron
Lining of the digestive tract and organs
Endoderm
Cnidarians are an example of this kind of animal
Diploblastic
Have only endoderm and ectoderm
Diploblastic animals
Bilaterally symmetrical animals are an example of
Triploblastic animals
Ectoderm, endoderm, and mesoderm
Triploblastic animals
Fills the space between ectoderm and endoderm
Mesoderm
Gives rise to muscles and most organs
Mesoderm
Contain a body cavity
Triploblastic animals
A fluid- or air-filled space between the digestive tract and the outer body wall
Body cavity
Cushions and suspends organs
Internal fluid
Body cavity surrounded by tissue derived from mesoderm
Coelom
Body cavity formed between the mesoderm and endoderm
Hemocoel
A fluid in Hemocoel that transports nutrients and waste throughout the body cavity
Hemolymph
Spiral cleavage and determinate cleavage
Protostome development
Radial and indeterminate cleavage
Deuterostome development
The planes of cell division are diagonal to the vertical axis of the embryo
Spiral cleavage
Rigidly determines the developmental fate of each embryonic cell very early
Determinate cleavage
The planes of division are either parallel or perpendicular to the embryo’s vertical axis
Redial cleavage
Each cell produced by early cleavage is able to form a complete embryo
Indeterminate cleavage
Splitting of solid masses of mesoderm forms the coelom
Protostome development
Mesoderm buds from the wall of the archenteron to form the coelom
Deuterostome development
An indentation in the gastrula that leads to the formation of the archenteron
Blastopore
Blastopore becomes the mouth
Protostome development
Blastopore become the anus
Deuterostome development
“True animals”; all animals except for sponges and few other belong to
Eumetazoans
Most bilaterians are
Invertebrates
What are the 3 clades of Bilaterians
Deuterostomia
Ecdysozoans
Lophotrochozoa
A crown of ciliated tentacles used for feeding
Lophophore
Developmental stage in molluscs and annelids
Trochophore larva