Deuterostomes Flashcards
In deuterostomes the blastospore becomes what? What type of cleavage to they have?
The anus. They have a radial cleavage.
What organisms are considered Echinodermata?
Sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids
Echinodermata have what type of symmetry?
Pentaradial symmetry.
What type of symmetry do Echinodermata have as larva?
Bilateral symmetry
What type of symmetry do Echinodermata have as adults.
Pentaradial symmetry
What type of surfaces do Echinodermata have?
Oral and aboral surfaces
Many are capable of what?
Regeneration
Their nervous system is what?
A nerve ring with branches
The epidermis covers what?
Endoskeleton
The endoskeleton is composed of calcium carbonate plates called what?
Ossicles
They can be joined in what two types of ways?
Tightly or Loosely joined
They have what type of vascular system?
A water-vascular system
Water enters through the what?
madreporite
Water is used to fill what, which in turn moves what?
Used to fill ampullae. Which moves tube feet.
What type of canals extend from what canal into each arm?
Radial canals extend from ring canal into each arm.
What are the FIVE groups of Echinodermata?
- Crinoidea
- Asteroidea
- Ophiuroidea
- Echinoidea
- Holothuroidea
Characteristics of Crinoidea?
- Crinoids, sea lilies, feather stars
- Early diverging
- Sessile, bottom-dwelling
- Feathery, branched arms surround mouth with tube for feeding
- Oral surfaces face up
Characteristics of Asteroidea?
- Sea stars and sea daisies
- Marine predators
- Have 5 arms (or multiples of 5) which are thick and tapered
- Can drop and regenerate arms
- Tube feet used for locomotion
Characteristics of Ophiuroidea?
- Brittle stars and basket stars
- Largest group
- Thin, Untampered arms extended from cental discs
- Easily autonomized
Characteristics of Echinoidea?
- Sea urchins, sand dollars, sea biscuits, sea cookies
- Lack arms
- Oral surface expands during development to cover almost entire body.
- Protective moveable spines
- Ossicles fused into test/shell
Characteristics of Holothuroidea?
- Sea cucumbers
- Soft, muscular bodies
- Secondarily bilateral
- Pentaradial symmetry still evident in 5 grooves along body wall
- Use evisceration as a defense mechanism
What is evisceration?
When threatened, will protrude internal organs and later regenerate damaged body parts
Chordates have an endoskeleton with what for muscle attachment?
An internal Rod
An endoskeleton allows what?
Bodies to swing from side to side when swimming
What are the 4 chordate features?
- Nerve Cord-Dorsal, hollow nerve cord (becomes brain and spinal cord)
- Notochord-Support for nerve cord (Vertebral column in vertebrates)
- Pharyngeal Slits-Connect to pharynx (Pharyngeal pouches present in all vertebrate embryos)
- Postanal Tail
What are the 2 groups of invertebrate chordates?
Urochordata and cephalochordata