Deuterostomes I

Question 1

Deuterostome phyla

Answer 1

Echinoderms
Hemichordates
Chordates

Question 2

What do the phyla of deuterostomes have in common?

Answer 2

Deuterostomy

Radial cleavage

Question 3

Deuterostomy

Answer 3

Second hole in embryo forms the mouth

Question 4

5 classes of echinoderm

A ECHO

Answer 4

Asteroids - Starfish
Ophuroids- Brittle stars 
Echinoids- sea urchins 
Holothurians- sea cucumbers 
Crinoids - sea lilies and feather stars

Question 5

4 important facts about echinoderms

Answer 5

Pentaradial symmetry
Water vascular system
Endoskeleton
Marine

Question 6

Madreporite

Answer 6

Key to echinoderms circulatory system; acts as a calcareous opening that filters water in and out of the body

Question 7

What makes the pentaradial symmetry of asteroids not perfect?

Answer 7

Madreporite

Question 8

How to we know pentaradial symmetry is secondary?

Two reasons

Answer 8

Echinoderm larvae have bilateral symmetry before they metamorphosis to have pentaradial symmetry

Echinoderm fossils often have bilateral symmetry

Question 9

Aboral

Answer 9

Side or end furthest from the mouth in echinoderms

Question 10

How do starfish feed?

Answer 10

Extension of the stomach out of its mouth where the prey is first externally digested with digestive enzymes before being drawn into the digestive glands.

Question 11

Tube feet

Answer 11

Tubular projections on the oral side of an echinoderm which are operated by hydraulic pressure and are used in locomotion and feeding.

Question 12

Water vascular system

Answer 12

System of canals in echinoderms which uses water drawn in through a Madreporite to create a hydraulic pressure that moves tentacles and tube feet

Question 13

What type of skeleton do starfish have?

Answer 13

Endoskeleton

Question 14

What is starfish skeleton made of?

Answer 14

Calcium carbonate plates called ossicles

Question 15

Sea urchin forms of defence

Answer 15

Spines

Pedicellaria

Question 16

Sea urchin spines

Answer 16

Spikes made of calcium carbonate that are sharp enough to puncture skin

Question 17

Pedicellaria

Answer 17

Small claw shaped appendage that sit in between the spines and are used to chop larvae.

Question 18

Aristotle’s lantern

Answer 18

Mouth apparatus of sea urchins. Includes powerful set of jaws and 5 sharp teeth like structures.

Question 19

How do sea urchins feed?

Answer 19

Use a structure called Aristotle’s lantern to scrape algae off of rocks
(Filter feeders)

Question 20

What is a sea urchins skeleton called

Answer 20

Test

Question 21

What does the test of sea urchins exhibit?

Answer 21

Pentaradial symmetry

Question 22

What have some sea urchins reinvented ?

Answer 22

Bilateral symmetry; evolved secondary bilateral symmetry on top of pentaradial symmetry. It is likely an adaption to burrowing.

For example sand dollars from the order Clypeasteroida

Question 23

Cuvierian tubules

Answer 23

Clusters of fine tubes that are used by sea cucumbers to entangle and immobilise prey

Question 24

Ossicles

Answer 24

Small calcareous elements found in echinoderms and often embedded in the dermis of the body wall

Question 25

Two classes within hemichordata phylum

Answer 25

Enteropneusts (acorn worms)

Pterobranchs

Question 26

What type of body do enteropneusts have?

Answer 26

Three part body

Proboscis
Collar
Trunk

Question 27

How do enteropneusts feed?

Answer 27

Pharyngeal slits

Question 28

Pharyngeal slits

Answer 28

Filter feeding organs found in deuterostomes