Lectures: Deuterostomes

Question 1

What are the main differing traits of Deuterostomes?

Answer 1

28: main traits of Deuterostomes
* Deuterostome (mouth second)
development

Question 2

What are the 2 main Deuterostomes?

Answer 2

1. Echinodermata
2. Choradata

Question 3

Echinodermata characteristics:

Answer 3

• Echinodermata = “prickly skin”
• Includes sea stars, sea urchins, sand dollars, sea cucumbers
• Larvae have “bilateral symmetry”
• Adults have “pentaradial symmetry”, which is Radial symmetry in multiples of 5
• Loss of cephalization, meaning they can interact with environment using all five sides at once
• Endoskeleton: internal skeleton
  for protection and support made of calcium carbonate
• Mouth on ventral side
• Water vascular system:
  a) Extends down each arm, ending
  with tube feet that have tactile and
  movement functions
  b) Tube feet controlled by bulblike
  ampullae

Question 4

What are the main differing traits of Echinodermata?

Answer 4

29: main traits of Echinodermata:
* Adult pentaradial symmetry
* Loss of cephalization
* Water vascular system

Question 5

What are the 3 main Chordata lineages?

Answer 5

1. Cephalochordata
   (lancelets)
2. Urochordata
   (tunicates)
3. Vertebrata
   (jawless fish, sharks/rays, bony fish, amphibians, reptiles/birds, mammals)

Question 6

Chordata characteristics:

Answer 6

1. Notochord
   - rigid yet flexible
   - becomes invertebrate discs in vertebrates
2. Dorsal hollow nerve chord
   - lost in urochordates
3. Pharyngeal gill slits
   - used for filter feeding in aquatic chordates
   - only present in embryonic stages of tetrapods
4. Post-anal tail

Question 7

What are the main differing traits of Chordata?

Answer 7

30: main traits of Chordata:
* Pharyngeal gill slits
* Dorsal hollow nerve chord
* Notochord
* Post-anal tail