What are 2 characteristics on an animal?
- 1) classified b/t 30 and 35 phyla
- 2) all phyla were present in the beginning of the Cambrian along with a great variety of now-extinct phyla recorded in the Burgess shale.
Name 2 characteristics of a protest?
- 1) unicellular
- 2) eukaryotic
2 Characteristics of bacteria
one of the 2 prokaryotic domains, second is archea.
Hox Genes are what?
genes that specify segment identity- whether a segment of the embryo will form part of the head, thorax, or abdomen, for instance.
genes are crutial for number & plavement of embryonic segment structures (legs, eyes,etc.)
Distinguish between Radial and Bilateral Symmetry.
Radial:Sessile or drifting, no cephalization.
Bilateral Symmetry: Motile, active lifestyle, and has a cephalization (head), sensory organs, expected movement, coordination, and high metabolism.
what is an acoelomate?
solid bodied animal lacking a cavity b/t gut and outer body wall.
distinguish amoung acoelomate, Pseudoclomate animals and coelomate
Acoelomate(flatworms) do NOT have a coelum(body cavity)
Pseudocoelomate(roundworms) have a body cavity but does not develop from splitting of the mesoderm.
Coelomate animals( fish, shrimp) have a body cavity lined with mesoderm cells.
functions of the body cavity?
- 1) provides space for organs
- 2) cushions organs
- 3) can function as a hydrostatic
- 4) Coelomates have a more efficient digestive system
Distinguish between dipoblastic and tripoblastic.
- Dipoblastic are radial symmetry. (comb jelly)
- Tripoblastic are Bilateral symmentry(coelomates, Psuedocoelomates, Ascoelomates)
Differences in Spiral and radial cleavage
- Spiral: determinate cleavage
- Radial: Indeterminate cleavage
Differences in determinate and Indeterminate cleavage
InDeterminate: if these cells are separated from each other, each has the potential to develop into entire organism on its own.
Determinate: If these cells are separated, they will die. Neither has the potential to develop into an organism on its own.
Protosomes and Deuterostomes
Pattern of cleavage is the spiral cleavage and determinate cleavage for Protosome.
solid masses of mesoderm split and form coelom
- Radial Cleavage and Indeterminate cleavage for Deuterostomes
- Folds of archenteron form coelm