Bio lab quiz 4 Lab 10

Question 1

Echinoderms

Answer 1

Classes that constitute this are:

• Crinoidea(sea lilies)
• Asteroidea (sea stars)
• Ophiuroidea (brittle stars)
• Echinoidea (urchins &sand dollars)
• Holothuroidea (sea cucumbers)

Question 2

Ambulacral grooves

Answer 2

-they align the tube feet (there’s 5 of them).

Question 3

Madreporite

Answer 3

-water vascular system communicates with external environment through a special skeletal plate called the madreporite (water exits and enters through this)
-Crinodea doesn’t have an external one
Asteroidea’s one is aboral
Ophiuroidea’s is oral

Question 4

Pedicellariae

Answer 4

• existent in Asteroidea and Echinoidea
• are pincer like structures and develop from the skeleton
• Most of these keep debris and settling larvae off the body, and others are used to defend against larger organisms

Question 5

Aboral surface

Answer 5

-side opposite the mouth of the organism

Question 6

Oral surface

Answer 6

-the side with the mouth of an organism

Question 7

Deuterostomia

Answer 7

Organisms in which the anus develops first then the mouth second
-consists of echinoderms and chordates

Question 8

Articulated arms

Answer 8

• existent in ophiuroidea (in all five of their arms)

- Their arms contain internal vertebral plates(which are the components of the endoskeleton)

Question 9

Tube feet

Answer 9

• used both for locomotion and feeding
• in asteroidea it is suckered
• in Ophiuroidea, there are no suckers on this

Question 10

Endoskeleton

Answer 10

-in the five arms of ophiuroidea, the arms are articulated and contain internal vertebral plates which constitute the endoskeleton

Question 11

Water vascular system

Answer 11

-it is a series of internal hydraulic canals and specialized tube feet, that with the endoskeleton, provide a system primarily for locomotion and food gathering
— this communicated with the external environment through a special skeletal plate called the madreporite (this structure serves as an a venue for sea water to enter or leave the system).

Question 12

Secondary pentaradial symmetry

Answer 12

-all adult echinoderms are characterized as having secondary pentaradial symmetry (larvae exhibit bilaterial symmetry)

Question 13

Feeding strategies and structures

Answer 13

Tube feet is one structure that enables this

-Asteroidea prey on mussels, use tube feet to open valves of mussels

Question 14

Defense mechanisms

Answer 14

-Evisceration (holothuroidea (sea cucumbers) utilizes this)-
ejection of internal organs
-bright colors- toxic compounds
In echinodea, spines can be used for defense

Question 15

Respiration

Answer 15

-holothuroidea- breathes through anus

Question 16

Reproductive strategy of this group

Answer 16

External fertilization
Eggs and sperm released into water column
No parental care
Planktonic larval stage

True for all echinoderms

Question 17

Sea star wasting syndrome

Answer 17

“Sea star wasting disease or starfish wasting syndrome is a disease of starfish and several other echinoderms that appears sporadically, causing mass mortality of affected starfish.[1] There are around 40 different species of sea stars that have been affected by this disease. The disease seems to be associated with raised water temperatures. It starts with the emergence of lesions, followed by body fragmentation and death.”