L 11 - protostomes vs deuterostomes

Question 1

deuterostome/protostome dogma

Answer 1

origins of mouth differ

1. blastopore - P = mouth; D = anus
2. origin of coelem via 2 mechanisms - P = schizocoely. D = outpocket = enterocoely.
3. origin of mesoderm. P = blastopore cells pigrate and split. D = epithelial cells inpocket from archenteron.
4. cleavage P = spiral and determinate cleavage. 5. multiciliated cells. D = radial and intermediate cleavage. monoiliated cells.

Question 2

protostomes and mouth formation

Answer 2

only some do mouth first. other blastopore can be anus, (D), or other, or close up.

Question 3

protostome synapomorphies

Answer 3

dorsal cerebral ganglia form; circumesophageal connectives to ventral nerve cords.

Question 4

protostomes that have deuterostome development

Answer 4

nematomorpha

priapula

Question 5

2 classic developmental featues in deuterostomes

Answer 5

pharyngeal gill slits

trimeric body coelom