Bio Warm Up 6
Card Set Information
Bio Warm Up 6
Crazy Happy Funny Mad
In what animals do two major patterns of embryological development occur?
What do the embryos of the animals begin as?
Hallow balls of cells that indent to form a ball two cell layers thick with an opening called blastopore
In flatworms, annelids, mollusks, and arthropods, the mouth develops from or near the blastopore and are called what?
In what two groups of animals does the anus develop ffrom or near the blastopore and the mouth forms later.
Echinoderms and chordates
What represents a revolution in embryonic development?
In protostomes the development fate of each embryonic cell is _________________?
Fixed meaning each cell is destined to develop into a particular part of the animal and no other (determined development)
In deuterostomes embryo if the cells are ____________ at an early, each cell can develop into a complete organism
Separated (Indeterminate development)
Echinoderms were the first _____________
Echinoderms evolved more than __________ years ago
Echinoderms were the first to develop a __________
Exoskeleton or internal skeleton
What does echinoderm mean?
What is the Spine composed of?
Hard calcium-rich plates called ___________
ossicles that are just beneath the delicate skin
When ossicles first formed they were ___________ in living tissue and so are truly an endoskeleton
In adults the ossicles ___________
About how species are there for echinoderms?
6000 most are marine
What do echinoderms include?
sea stars, sea urchins, sand dollars, brittle stars, and sea cucumbers
What does the nervous system consist of?
a central ring of nerves from which five branches arise but there is no centralization of nerve function "brain"
What are echinoderms characterized by?
pentamerous radial symmetry - five appendages each containing a duplicate set of various internal organs
Echinoderms do not have what?
heart, brain, nor eyes, but some stars have light sensitive parts on their arms.
Where is the mouth situated?
On the underside and their anus on top except feather stars, seacuccumbers, and some urchins
What are the tentacle structures iof echinoderms called?
What do tube feet have?
Suction pads situated at their extremities which they use for locomotion.
What are the tube feet controlled by?
Water Vascular System