Download Deuterostomes Supplemental Instruction Iowa State University

Leader: Jenny
Deuterostomes
Course: Biology 211
Supplemental Instruction
Instructor: Raich
Iowa State University
Date: Sunday, October 12, 2008
1. Phylum chordate and Phylum Echinodermata are the two main deuterostome
phyla.
2. Fill-in-the-blank and circle the correct answer:
The name “echinoderm” means spiny skin. Members of this phylum are slow/fastmoving creatures, and they have radially/bilaterally symmetrical bodies, however,
their larvae are radially/bilaterally symmetrical. Their endoskeleton consists of
calcareous plates and they have tube feet. Echinoderms are known to have a water
vascular system which consists of hydraulic tubes that function in feeding,
locomotion, and breathing. Some organisms in this phylum have a very-well
developed capacity for limb regeneration (example of an organism that does this:
starfish)
3. What three characteristics present in echinoderms differentiates them from the
radiata? Triploblastic body plans, deuterostome embryogenesis, bilaterally
symmetrical larvae
4. List the four characteristics that are present in all chordate at some point in their
life cycle and describe their function:
Notochord: longitudinal, flexible rod between the gut and nerve cord. It provides
internal skeleton in invertebrate chordates, modified as part of a stiff jointed
skeleton in vertebrates, NOT a spinal chord
post-anal tail: provides propulsion in aquatic and marine species, balance and
other functions in terrestrial species
dorsal hollow nerve cord: other animals usually have a solid nerve cord that is
ventral to the gut, forms the CNS (spinal cord and brain in vertebrates)
pharyngeal slits: modified for filter-feeding in invertebrate chordates, modified
for gas exchange in some (eg: fish), pharynx—the part of the digestive system
just posterior to the mouth
5. Please draw the basic chordate we discussed in class and be sure to label the four
chordate characteristics from #4.
6. Examples of chordate organisms fill-in-the-blank:
Cephalochordates include lancelets which are small marine animals that obtain nutrition
by filter feeding. Their muscles are serially arranged which is a form of segmentation.
Tunicates or sea squirts are examples of urochordates. They are mostly sessile, marine
organisms that filter feed. Hagfish are marine, eel-like creatures which have a
cartilaginous skull, no vertebrae, no jaws, no hard bones, no paired fins, and do have
four pairs of frontal tentacles. They feed by being scavengers and predators and feed on
both living and dead organisms.
True/false:
T/F Both echinoderms and chordates have the ability to regenerate lost limbs.
Review Quiz:
1. Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain
nutrients and water from the vascular tissues of the trees. The trees derive no known
benefits from the dwarf mistletoes. Which of the following best describes the
interactions between dwarf mistletoes and trees?
A. facilitation
B. competition
C. mutualism
D. parasitism
E. commensalisms
2. Annelids are abundant and successful organisms characterized accurately by all of the
following except:
A. some parasitic forms
B. a complete digestive system
C. segmentation
D. a cuticle made of chitin
E. a hydrostatic skeleton
3. A butterfly goes through which process below:
A. flex
B. complete metamorphosis
C. radiate
D. incomplete metamorphosis
E. flux
4. Fungi are:
A. heterotrophic
D. saprobes
B. eukaryotic
E. all of the above
C. made of hyphae
5. Medusa and polyp body plans are typical of which group:
A. Parazoa
B. Cnidaria
D. Platyhelminthes
E. Porifera
C. Echinoderms