Test 3 Flashcards
Phylum Annelida =
the segmented worms
Name my Phylum: triploblastic, bilateral symmetry, protostome development, cephalization, true coelom, segmentation
Annelida
Where are Annelids on the Phylum chart?
between Mollusks and Lophoporates
The following characteristics belong to what Phylum? Most with one or more pairs of chitinous setae, vermiform, Flexible/ thin body wall, Closed circulatory system & complete digestive tract, Gas exchange across body wall, Segmentation, Metanephridia
Annelida
An Annelid’s conspicuously long body is known as what?
vermiform
The segmentation of Annelids is known for repetition, this pattern is known as what?
metamerism
The Annelid’s excretory structures are called what?
Metanephridia
Annelida means what?
ringed
The body wall of Annelids often plays an important role in ______ and _____ but, it must be kept moist for gases to diffuse, so annelids live in aquatic or moist places.
locomotion and gas exchange
Where do Annelids live and why?
Aquatic or moist places because, its body wall must be kept moist for gases to diffuse.
In polychaetes and earthworms, segments are separated from one another internally by partitions called ____.
septa
The segmentation of Annelids helps with ______. The coelom is divided into segments, and each segment has its own muscles allowing the animal to lengthen one part of its body while shortening another. Changes in pressure of one segment (affects/does not affect) pressures in other segments.
locomotion, does not affect
The large, compartmentalized coelom of Annelids serves as a _______.
hydrostatic skeleton`
Each segment of an Annelid has a pair of metanephridia used to ____________ and ____________.
excrete wastes and regulate water within the coelom
The inner end of an Annelid’s metanephridium opens into the ______ as a ciliated funnel (the nephrostome) and the other end opens to the _______ through a nephridiopore.
coelom, outside
Class _______ (about 64% of all annelids) include animals like sandworms & tube worms. Subclass ________ (about 27% of all annelids) include earthworms. Subclass ________ (about 5% of all annelids) include leeches.
Polychaetes, Oligochaetes, Hirudinea
Class Polychaeta and Clitellata (Subclasses Oligochaete and Hirudinea) are _______ meaning they do not molt.
Lophotrochozoa
Most _____ lack setae, while ____ and ______ have them.
leeches/Hirudinea, Cl. Polychaeta and SC Oligochaete
Class Clitellata have structure called ______. It secretes a cocoon for development of embryos (the “midsection”).
clitellum
Name my class. most live in salt water, have parapodia, well-developed head, dioecious, some active & others sedentary.
Class Polychaeta
This class is probably the most primitive group of annelids. They live in habitats from intertidal zone to extreme depths; quite a few live in brackish or fresh water, at least 2 sp. are terrestrial. Their size range is from 1 mm to over 3 m. Each body segment typically has a pair of parapodia.
Class Polychaeta
Each body segment of Polychaete typically has a pair of paddle-shaped appendages called _____ that function in ________ and ______.
parapodia, locomotion and gas exchange
Class Polychaeta are often called bristle worms because of all their bristles, called ____, on each side.
setae
In _________ polychaetes, setae, combined with snake-like body waves, help the worm to move along. In _______ {Eurythoe spp}, the bristles have evolved into defensive organs filled with venom which can break off in skin & cause irritation. Setae found in _________ or _______ worms that live in tubes or burrows have often evolved into hooks to help anchor the worm in place.
free-living, Fireworms, sessile or sedentary worms