Download Unit 5 Notes #6 Segmented Worms Fill In - Mr. Lesiuk

Name: ___________________
Date: __________
Unit 5 Notes #6 - Phylum Annelida: Segmented Worms
A) Body Plan:
Similarities To Phylum Aschelminthes (Nematoda):
1. __________________ symmetry
2. _______________________________(Ectoderm, endoderm, mesoderm)
3. Complete digestive system (mouth to anus).
Differences:
-Contains a “___________________”, this is considered to be a “________________
_______________”. Unlike the “Pseudocoelom”, this cavity is not just fluid-filled,
but it is also ________________________________
This provides several____________________:
1) This coelom separates the body wall from the gut. Thus______________________
_____________________________________________________________-.
2) The _________________________________may____________________________
__________________, including wastes, food and dissolved gases in the body.
3) The coelom ________________________________where true systems and their
organs can operate. (Ex, stomach, heart, lungs etc.)
-Annelida are the first to exhibit_______________________: “__________________
__________________________________________________________. Most segments
contain duplicate structures for locomotion, excretion, muscle and nervous tissue.
-This segmentation is visible on the outside of these worms.
B) Annelida _______________:
1. Class____________________: These are mainly _______________________that
live in sand or mud of shallow coastal areas.
-They usually have pairs of
paddle-like appendages that are
tipped with numerous bristles.
2. Class______________________: Most are terrestrial but some are freshwater,
found burrowed into soil and mud.
-They do not have any leg-like appendages but do have________________________
________________________________________. Example : _____________________
3. Class ________________: These are the _______________
-Most live in freshwater as______________________________.
-They have a sucker at each end of their body, they____________________________
_______________________________________________ to facilitate “blood sucking”
THE EARTHWORM
A) _____________________of the Earthworm:
-Adapted for ingesting leaf fragments, seeds, bodies of small animals and protists,
as well as rich organic soil.
-Soil and organic matter are sucked into the ____________ by the _______________
___________________
-Muscular action pushes the food through the narrow __________________ and into
the ____________________________________________
-The crop directs food matter into the ________________________________
-The gizzard, with help of sand particles, ____________________into smaller pieces.
-At this point the food is___________________________________, which extends
from the gizzard to the anus.
-Gland cells of the intestinal wall, contain enzymes, which digest proteins, fats, and
carbohydrates, including cellulose.
-The______________________________________________________, while _______
passes out through the __________
-The muscular action that pushes the food along is called____________________. It
results from the alternate contraction and relaxation of certain muscles to create a
wave motion along the tube.
B) ______________System of Earthworm:
- Need a ____________circulatory system, as animals get larger,_________________
_______________________________________________________________________
____________________________________________________________________.
-Special circulatory tissue called ___________is directed through a continuous
system of muscular tubes called_____________________. Blood is red due to
__________________
-Blood flows through the dorsal (top/back) vessel. From here, _________________
________________________________direct the flow to the ventral (bottom/belly)
vessel.
-In each segment, the ventral vessel branches to send blood out to the body wall.
-Other branches take blood to the intestine where the blood absorbs nutrients.
-_________________ return the blood to the dorsal vessel.
C) Respiration :
-This occurs by __________________________________________________________
__________________________________________
-Kept moist by ________________________________and by the ____________which
prevents desiccation (drying out)
D) Nervous System:
-_____________________ is located above the pharynx, the brain is ______________
___________________________________, which runs the length of the worm.
-In each segment there are sensory and motor nerves that branch off of the ventral
nerve cord.
-These ______________________________are sensitive to______________________,
____________________________________________________
E) Reproduction in Earthworms
:
- Earthworms are ____________________________________________________
The _________system:
1. Two pairs of small ___________________________________(segments 10 and 11)
2. Two large __________________________________________________________.
3. The openings of two sperm carrying tubes called vasa deferentia are located on
the ventral side of segment 15.
The _____________system:
1. A pair of small ______________in segment 13
2. Two pairs of ___________________________in segments 9 and 10, which_______
___________________________________________________________during mating.
- During the process of mating two worms line up beside each other pointing in
opposite directions.
- The _____________________________________________around the two worms,
this sheath will ensure they stay together.
- Later each worm secretes a cocoon around its clitellum, and ___________________
__________________________________________________________
- The worm backs out of the cocoon; as the cocoon passes the openings of the
seminal receptacles,______________________________________________________
_______________________________________________.
- Fertilization now takes place in the cocoon.
- When the worm leaves the coccoon, the ends of the coccoon close over.
- The young worm emerges from the cocoon in 2-3 weeks, it appears similar to the
adult stage.
- Worms do not ________________________________until they are ____________
__________________.