Phylum Echinodermata

Question 1

Ossicles in echinoderms

Answer 1

Class asteroidea & ophiurodea: ossicles around periphery & down arms.
Class echinoidea: ossicles fused into a test.
Class holotburoidea: ossicles embedded in body wall tissue
Class crinoidea: ossicles connected by ligaments

Question 2

Water vascular system

Answer 2

It is a hydraluic system, consists of a series of fluid filled canals, connective numerous tube feet, used for locomotion, respiration and feeding.

Question 3

Pedicellaria in echinoderms

Answer 3

Only found in asteroidea and echinoidea, remove fouling organisms, food capture, some inject venom

Question 4

Respiration in echinoderms

Answer 4

Protected gills: paxillae protected gills.
Exposed skin gills: projections of the coelom (papula)
Tube feet: respiration via diffusion

Question 5

Characteristics of class asteroidea

Answer 5

Usually 5 arms, central mouth on oral surface, anus & madreporite on aboral surface , tube feet in ambulacral groove on oral surface, pedicellaria present , respiration via papulae & tube feet, regeneration

Question 6

Feeding in asteroidea

Answer 6

Most Are carnivores, mouth leads to two-part stomach (cardiac & pyloric stomach) , cardiac stomach everted through the mouth during feeding, pyloric stomach connects to digestive gland in each arm

Question 7

Regeneration in asteroidea

Answer 7

Arms can undergo regeneration , forces exerted by the animal’s own muscle and the grip of the attacker.

Question 8

Characteristics of ophiurodea

Answer 8

5 slender arms, calcium carbonate ossicles , WVS, ambulacral groove closed, no pedicellaria or skin gills, regeneration , mouth & madreporite on oral surface , no anus , locomotion via arms

Question 9

Feeding and respiration in ophiuroidea

Answer 9

Feeding: active predators( use arms to capture prey) , some Are suspension feeders, scavengers.
Respiration : bursa- cilia lined sacs

Question 10

Characteristics of class echinoidea

Answer 10

Marine , pentamerous symmetry, separate sexes, test is globular (regular ) , heart urchins and sand dollars (irregular), aristotle lantern (5teeth) , tube feet used for locomotion, respiration and feeding), spines also used for locomotion, respiratory podia in ambulacral area

Question 11

Feeding in echinodermata

Answer 11

Aristotle’s lantern and mouth- esophagus- stomach-intestine -anus

Question 12

Characteristics of holothuroidea

Answer 12

Elongated along the oral/aboral axis, lack arms, endoskeleton , locomotion crawlingvalong the substrate using podia, others move peristaltic locomotion via muscle contractions , breaths through anus, madreporite internal

Question 13

Feeding in holothuroidea

Answer 13

They Are suspension and deposit feeders, oral tentacles Are modified tube feet, good gathered through mucus in tentacles

Question 14

Respiration in holothuroidea

Answer 14

Pair of respiratory trees in holothurian, trees Are ventilated by muscular contractions of the cloaca , inhalation involves openings the anus , gas exchange by diffusion

Question 15

What Are cuvieran tubules ?

Answer 15

Specialised defence system, tubules at base respiratory tree, engulf and tangle prey.

Question 16

Characteristics of crinoidea

Answer 16

Marine, 5 or more arms, stalked or non-stalked, leathery skin with calcareous plates, no madreporite, no spines , no pedicellaria , filter-feeders on zooplankton -respiration via diffusion tube feet .

Question 17

Feeding in crinoids

Answer 17

Use arms, tube feet and mucus nets food, hold arms up in the water column to capture food, captured food moved by tube feet to ambulacral groove, cilia and mucus move food to mouth

Question 18

Characteristics of echinodermarta

Answer 18

All marine, deutorostomes, endoskeleton ( connective tissue & calcareous ossicles, water vascular system, bilaterally larvae and pentaradial adults, pedicellaria