Ch.17 Textbook Review Questions

Question 1

What characteristics of phylum Annelida distinguish it from other phyla ?

Answer 1

coelomate, lophotrochozoan protostomes , exhibit segmentation

Question 2

How are members of clade Clitellata distinguished from other annelids

Answer 2

Monoecious w/ direct development, no parapodia

Question 3

Explain how the hydrostatic skeleton of annelids helps them burrow

Answer 3

Coelom filled w/ fluid at a constant volume they can contract their circular (contracts like a belt) and longitudinal muscles (contracts- smaller /wider

Question 4

Define
prostomium
peristomium
pygidium
radioles
parapodium

Answer 4

prostomium- The part of the head located in front of the mouth
peristomium -One of two parts forming the annelid head; it bears the mouth

pygidium- where the segmented body ends

radioles- Featherlike structure extending from head of some sedentary polychaetes; used in feeding on suspended particles

parapodium- flap like appendages on segment

Question 5

What is the function of the clitellum and cocoon

Answer 5

clitellum is important for reprod bc it secretes mucus around the worm during copulation

cocoon- receives eggs and sperm where embryonation occurs

Question 6

How do leeches obtain food

Answer 6

sucking blood thru their hosts

Question 7

what is the largest siboglinid known, and how is it nourished

Answer 7

Giant pogonophorans (Riftia pachyptila)

The largest known siboglinid (which reaches 1.5 m in length and 4 cm in diameter) is found in the deep water of the Pacific Rim.

It uses its trophosome, which is buried in the sulfide-rich sediments, to nourish its body.

Question 8

What is the evolutionary significance of segmentation and the coelom to its earliest lophotrochozoan possessors?

Answer 8

the coelom appears to have evolved independently
segmented body has arisen 3 times