Ch 32 introduction to animal diversity

Describe a coelom and explain its role in animal classification

Coeloms are important because they allow for the separation and compartmentalization of different biological functions in the body. Animals lacking coelom have to rely on diffusion to transport important nutrients throughout the body.

Describe why only organisms with indeterminate cleavage can have identical twins

Indeterminate cleavage is cleavage that results in in cells that maintain the ability to develop into a complete organism. IDENTICAL TWINS result from indeterminate cleavage. Determinate cleavage results in cells whose future differentiation pathways are determined at an early developmental stage resulting in specialization. Much higher chance if they are indeterminate b/c the embryos can break off and form genetically identical organisms

Compare and contrast Parazoa and Eumetazoa and give an example of a Parazoan

Parazoa includes porifera, Eumetazoa is everyone else, and means "true tissue"

diploblastic

Phylum Porifera, Cnidaria- blastula forms two groups of cells that give rise to two body layers ectoderm and endoderm

Explain the difference between Radiata and Bilateria and give examples of animals that display these two body plans

Radiata relates to radial symmetry, and Bilateria relates to bilateral symmetry

Describe the major features of body plans

Symmetry- bilateral and radial Body cavity structure- protostomes(determinate cleavage), deuterostomes(indeterminte cleavage) Segmentation- allows specialization External appendages-

Describe how movement relates to animal traits and discuss whether movement is required to be classified as an animal

all animals move to some degree, because they have a nervous system that responds to stimuli, but the movement may be minimal

Identify how an exoskeleton/cuticle categorizes organisms in modern taxonomy

as crustacea or arthropoda, nematoda: because it provides predatorial protection, but doesn't allow for greater growth or support of limbs

Summarize why modern animal classification is different from historic classification

because molecular data provides a more accurate

Identify the relationship between symmetry and cell layers in the embryo

bilateral symmetry yields 3 germ layers, the endo, meso, and ectoderm

triploblastic

chordata, echinodermata, mollusca- the blastula forms three groups of cells that give rise to three layers ectoderm mesoderm endoderm

Describe the differences between triploblastic and diploblastic embryos

diploblastic embryos develop into cnidarians, triploblastics form into bilateral animals

Identify organisms with notochords

found in chordata

Identify how lophophores or trochophore larvae are used to categorize organisms in modern taxonomy

lophphorata- includes all protostomes

List the characteristics shared by most members of the animal kingdom.

multicellularity heterotrophy no cell walls nervous tissue movement sexual reproduction extracellular matrix cell junctions(anchoring, tight, gap) special clusters of HOX genes similar rRNA

Relate the terms protostome and deuterostome to determinate and indeterminate cleavage

protostome yields determinate cleavage and deuterostomes yield indeterminate cleavage

Describe the advantages of segmentation and identify examples of segmentation in organisms

segmentation allows for specialization. muscles, clitellum, head