Phylum Annelids Flashcards
Phylum Annelida where there is a true _
Coelom
what is eucoelom lined with
peritoneum, of mesodermal origin
what are 4 eucoelom advantages
1) eucoelom with peritoneum allows for segmentation (compartmentalization of body)
2) individual segments can move independently greatly increasing efficiency of burrowing and other movements
3) mesenteries (which is extension of peritoneum)
4) peristalsis (muscles surround the gut)
what do annelids and nematodes have in common (5 answers)
bilateral symmetry and internal cephalization
complete digestive tract
parasites
no resp system
restricted to wet or moist environments
how do annelids and nematodes differ (muscles and excretory system)
nematodes have muscular pharynx, and no muscles in the intestine (gut), and longitudinal muscles in the body wall
annelids have circular and longitudinal muscles in body wall and digestive system
nematodes excretory system is diffusion
annelids excretory system is nephridium (kidney like)
what are chloragogen cells
modified peritoneum covering digestive system
convert waste products of protein metabolism into ammonia and urea
also synthesize glycogen and fat from excess calories
What did chloragogen cells evolve into?
liver
What type of circulatory system do annelids have
closed
what is difference between open and closed circulatory system
open it goes from pump to ostium to valve to artery to hemocoel
closed it goes from pump to valve to artery to capillaries to veins
what are aortic arches
hearts
explain annelid circulation
some have aortic arches which regulate blood pressure
peristaltic pumping is done by muscular dorsal vessel
respiratory pigment (hemoglobin) is present in blood of annelids
what type of respiratory system do annelids have
diffusion (marine have gills)
explain nervous system of annelids
ventral nerve cord connected to a dorsally located cerebral ganglia
each segment has a pair of ganglia
Class oligochaeta
(few setae)-earthworms
class polychaeta
(many setae)-marine annelids
Class Hirudinea
leeches
digestive system of Oligochaeta
mouth>pharynx>esophagus>crop-storage>gizzard-grinding>intesting-enzymes
What does Oligochaeta intestine contain and what is it surrounded by
contain typhlosole
surrounded by chloragogen cells
Are oligochaetes monoecies or dioecies
monoecies
what is ecological niche of earthworms, and how are they important ecologically
detritivores: enormously important in Recyling of nutrients
class polychaeta are often known as
tube worms
class polychaeta- some are _, some filter feeders in marine ecosystem
predators
what is pronounced in polychaeta
external cephalization
what is setae
bristles
what are two polychaeta characteristics
parapodia- fleshy extensions of each segment
relatively many setae are present
what is parapodia
fleshy extension of each segment
what is polychaeta repro?
dioexious with no permanent sexual organs
what type of development is polychaeta
indirect
Direct development def
form of newly born offspring resembles the parents
indirect development def
newly born offspring takes a different form compared to the parent
what type of predators are class Hirudinea
freshwater that are ectoparasites of vertebrates
what type of segmentation is present in Hirudinea
segmented externally, no setae
what two types of suckers do leeches have (where)
anterior and posterior
Hirudinea characteristic (5)
no setae
no septa, no internal segmentation
coelom is modified
circulatory system is modified
digestive system modified
