lecture 20 Flashcards
Deuterostomia have what characteristics of their embryos?
- radial, intermediate cleavage
- enterocoelous coelom
- blastopore dose not become mouth.
Why are Echinoderms so abundant in the fossil record?
They have calcareous endoskeletons that make them well-suited to fossilization.
What type of symmetry do echinodermata demonstrate?
They display a pentaradial symmetry as adults.
What does the root word “penta” mean?
It means 5
What is the symmetry of echonodermata larva?
They are bilaterally symmetrical
What is the leading hypothesis that conveys why echonodermata larva develop into pentaradial symmetrical organisms.
It is based off of Hox genes.
What is the basic morphological structure of Echinodermata?
They have oral and aboral sides.
They have a think epidermis that covers a endoskeleton made of ossicles.
What are ossicles?
They are small calcareous plates that make up the endoskeleton of Echinodermata.
What dose the root work -ossa- mean?
Bone
What dose the root word -echino- mean?
Spiny
What dose the root word -derm- mean?
Skin
True or false:
The Echinodermata have a unique water vascular system.
True.
Within Echinodermata, What is the network of hydraulic canals branching into extensions called?
They are called tube feet.
How do echinodermata connect to sea water?
Through madreporite.
What are madreporite?
Special porous ossicles found in echinodermata
What is the nervous structure of Echinodermata?
they have a diffuse nervous system with no defined central brain.
How do Echinodermata reproduce?
Through male and females broadcast spawning.
True or false:
Some Echinodermata brood eggs until hatching, forgoing broadcast spawning as females.
True.
What is the most well known Member of the Class Asteroidea?
The star fish
What dose the root word -aster- mean?
Star.