Echinodermata

Question 1

How is the body of an Echinodermata set up?

Answer 1

Both internal and external parts radiate from center of tern in 5 spokes

Question 2

What is the endoskeleton of an Echinodermata? What covers it?

Answer 2

Inside skeleton of hard calcareous plates. Covered in a thin skin

Question 3

What is unique to Echinodermata as a part of their modified coelom?

Answer 3

Water vascular system

Question 4

What is the water vascular system? Used for?

Answer 4

Network of hydraulic canals branching into tube feet

Used for: locomotion, feeding and gas exchange

Question 5

How do Echinodermata reproduce?

Answer 5

Release of gametes by separate sexes

Question 6

What are the 6 classes of the subphylum Echinodermata?

Answer 6

1- Asteroidea
2- Ophiuroidea 
3- Echinoidea 
4- Crinoidea 
5- Holothuroidea 
6- Concentricycloidea

Question 7

What is an example of the class Asteroidea of the subphylum Echinodermata?

Answer 7

Sea stars

Question 8

How many arms does the class Asteroidea of the subphylum Echinodermata have? What is one them?

Answer 8

5 arms but sometimes more

Rowan tube feet = part of water vascular system

Question 9

How do the class Asteroidea of the subphylum Echinodermata feed? (2)

Answer 9

Actively hunt prey

Use tube feet to pry open Bivalves and invert their stomachs into it

Question 10

Can the class Asteroidea of the subphylum Echinodermata regenerate?

Answer 10

Yes - regenerate lost arms and sometimes entire body from 1 arm

Question 11

What is an example of the class Ophiuroidea of the subphylum Echinodermata?

Answer 11

Brittle stars

Question 12

Explain the body of the class Ophiuroidea of the subphylum Echinodermata

Answer 12

Central disc with long flexible arms

Question 13

What does the class Ophiuroidea of the subphylum Echinodermata lack? What does this mean?

Answer 13

Their tube feet lack suckers

Must move by serpentine lashing of their arms instead

Question 14

What is 2 examples of the class Echinoidea of the subphylum Echinodermata?

Answer 14

Sea urchins and sand dollars

Question 15

Explain the body of the class Echinoidea of the subphylum Echinodermata (3)

Answer 15

No arms but have 5 rows of tube feet
Sea urchin =roughly spherical
Salad dollars =flattened disk shaped

Question 16

How do the class Echinoidea of the subphylum Echinodermata move? (2)

Answer 16

The rows of tube feet is used for locomotion

For sea urchins they can also move by pivoting their spines

Question 17

Explain the mouth of a sea urchin in the class Echinoidea of the subphylum Echinodermata?

Answer 17

Ringed by jaw-like structures adapted for Ewing seaweed

Question 18

What are 2 examples of the class Crinoidea of the subphylum Echinodermata?

Answer 18

Sea lilies and feather stars

Question 19

How do the 2 examples of the class Crinoidea of the subphylum Echinodermata move?

Answer 19

Sea lilies - attached to group by stalks

Feather stars - crawl using long flexible arms

Question 20

What is an example of the class Holothuroidea of the subphylum Echinodermata?

Answer 20

Sea cucumbers

Question 21

Explain the body of the class Holothuroidea of the subphylum Echinodermata (3)

Answer 21

Lack spines
Hard endoskeleton is reduced
Oral-aboral axis is lengthened

Question 22

Explain the tube feet on the class Holothuroidea of the subphylum Echinodermata

Answer 22

Still have 5 rows of tube feet - some around mouth for feeding tentacles

Question 23

What is an example of the class Concentricycloidea of the subphylum Echinodermata?

Answer 23

Sea daisies

Question 24

What is believed about the symmetry of the phylum Echinodermata? (2)

Answer 24

The radial symmetry is a derived trait

Ancestors were either bilateral or asymmetrical

Question 25

What is known about the larvae of the phylum Echinodermata? (3)

Answer 25

Larvae has bilateral symmetry
Undergoes metamorphism
Loose right side of body as it gets absorbed