Download B. Form and Function in Flatworms

Ch. 27 Worms and Mollusks (pg. 682)
27-1 Flatworms
Worms have a _________________________________ body
Move_______________________________ rather than ____________________
Most have _____________________________________ at anterior end
Allows worms to: ______________________________________________
A.What is a Flatworm? (Phylum ________________________)
Size: ______________________________________
Flatworms are ________, ____________ worms that have _____________ and
_________________________. They are the simplest animals to have 3___________
________________, _________________________ and _________________________.
Acoelomates –
Coelom –
No _____________ forms between the tissues of flatworms.
The _______________________ is the only body cavity.
B. Form and Function in Flatworms
Because bodies are _______, all flatworms rely on _______________
for some essential body functions such as:_________________________________
Free-living flatworms have organ systems for:_____________________________
Parasitic flatworms are ______________ in structure
1. Feeding
Free-living flatworms can be _______________ or _______________
Have a digestive cavity with a ____________ opening
Pharynx –
Parasitic worms feed on: ______________________________________________
Most do NOT need a _________________________________________
Because:
2. Respiration, Circulation, and Excretion
Many flatworms rely on _______________ to transport ______________________
and to remove ________________________________
Excretion
Flame cells –
They may also filter and remove:
Many flame cells are joined together to form:_________________________
that empties:___________________________________________________
3. Response
ganglia –
In free-living flatworms:
Eyespot –
Other:
Parasitic flatworms have:
Because:
4. Movement
Free-living flatworms move in 2 ways:
5. Reproduction
Sexual reproduction – Most free-living flatworms are:
hermaphrodite –
Process:
Asexual reproduction
fission Parasitic flatworms often have:
C. Groups of Flatworms – Enormously divers group
1. Turbellarians (Class ________________)
Turbellarians are _______-___________flatworms. Most live in _________
or __________ water.
Most are _________________, living in: _________________________________
Most are _____________________, the “_______________” freshwater worms
2. Flukes (Class ___________________)
Flukes are ______________ flatworms. Most flukes infect the ______________
________________ of their host.
Schistosoma mansoni life cycle (pg. 687; Fig. 27-5):
Primary host (in which it reproduces sexually) is the ________________
Intermediate host (where parasite reproduces asexually) is the __________
1) Blood flukes infect humans by:
Once inside they are carried to:
Where they:
The embryos are:
2) If they get in water, embryos develop into:
And infect:
3) New larva, from asexual reproduction:
Causes: _________________________
Problems:
3. Tapeworms (Class ____________________)
Tapeworms are ________, _________, _____________ worms that are adapted to
___________________________________________________________________.
They have NO _______________________
They are surrounded by:
Structure:
Scolex –
Used to:
Proglottids –
Mature proglottids contain both: ____________________________________
Testes –
After eggs are fertilized:
If food or water contaminated with tapeworm zygotes is consumed by
cows, fish, etc. (intermediate hosts):
If a human eats incompletely cooked meat with cysts:
27-2 Roundworms (Phylum __________________)
Among most numerous of all animals
A. What is a Roundworm?
Roundworms are ______________ worms that have ________________ and
digestive systems with ___________________________________________
Size:
Found:
Pseudocoelum –
Digestive tract with _____ openings - _______- within-a-______ body plan
Food moves in ________________________ through the digestive tract
Anus –
B. Form and Function in Roundworms
1. Feeding
Many free-living roundworms are:
Some soil-dwelling and aquatic forms eat:
2. Respiration, Circulation, and Excretion
Exchange gases and excrete metabolic wastes:
NO _____________________________
Depend on ____________________
3. Response
Simple nervous systems consisting of:
4. Movement
Hydrostatic skeleton -
5. Reproduction – sexual
Most have:
Use __________________________________
Parasitic roundworms have:
C. Roundworms and Human Disease
Most are _________________
Phylum is better known for species that _________ their hosts, including ______
1. Trichnosis-causing Worms
Trichinella life cycle – 2 common hosts are ________ and ________
Adult worms:
Female worms carrying fertilized eggs:
These larvae:
Larvae form:
Completes life cycle when:
Humans get by:
2. Filarial Worms
Found:
Live in:
Transmitted from one host to another by:
In severe infections:
Causes:
3. Ascarid Worms
Causes severe malnutrition in more than ______________________________
By:
Ascaris lumbricoides life cycle (pg. 692: Fig. 27-10)
1) Humans ingest:
2) Eggs travel to:
3) Larvae enter:
4) Larvae are:
5) Eggs are released and:
Related species affect:
4. Hookworms
Today, as many as __________________________________ are infected
Hookworm eggs hatch:
If they find an unprotected foot:
Travel through:
There, they:
D. Research on C. elegans (Caenorhabditis elegans)
________-___________ roundworms
Feeds on:
DNA was:
Have traced __________________ and __________________ of each body cell
Studying how:
27-3 Annelids (pg.694) Phylum _______________
Annelids are a distinct group probably closely related to:
Evidence for this is:
A. What is an Annelid?
Annelids are worms with _________________ bodies. They have a true
__________ that is lined with tissue derived from _____________.
Septa –
Most segments are ______________ but they may be ______________ to:
Setae –
Annelids have ________ - _________ - ___ - __________ digestive tract
B. Form and Function in Annelids
1. Feeding and Digestion Range from ___________________ to ________________
Many annelids get their food using a ______________
In earthworms:
Pharynx:
Crop –
Gizzard Food is absorbed:
2. Circulation
Closed Circulatory System –
Dorsal vessel:
Ventral vessel:
In each body segment:
Dorsal vessel functions like:
3. Respiration
Aquatic annelids breathe through:
Gill –
Land-dwelling annelids:
4. Excretion
Cellular wastes containing _____________ eliminated by:
Nephridia –
Digestive waste:
5. Response
Most have:
Consisting of:
Sense organs:
6. Movement
Have 2 major groups of body muscles
Longitudinal muscles:
Circular muscles:
Use setae:
7. Reproduction - most reproduce _________________
Some use _________________________ and have ______________________
Others are hermaphrodites:
clitellum -
C. Groups of Annelids
1. Oligochaetes (Class ______________) Ex. _____________________________
Oligochaetes are annelids that typically have ______________________ and
Relatively few __________ compared to ________________.
Most live in ___________________________________
Castings –
2. Leeches (Class ______________)
Most live:
Leeches are typically ____________________________ that suck the
___________ and ______________ of their _________.
About ¼ of all leeches are:
Body structure:
Once a wound has been made:
3. Polychaetes (Class _________________) ex. _______________________________
Polychaetes are _____________________ that have __________, ______________
_________________ tipped with ___________.
D. Ecology of Annelids
Importance of earthworms
In soil:
In food chains:
Marine annelids
27-4 Mollusks (pg. 701)
A. What is a Mollusk?
Mollusks are ________________ animals that usually have an ____________ or
_______________ shell.
Include:______________________________________________________________
Many mollusks share: _________________________________________________
Trochophore –
Also a characteristic of ______________ indicating that these 2 groups may be
_____________________
Molecular studies suggest that:
B. Form and Function in Mollusks
Like annelids, mollusks have true _________ surrounded by __________ tissue.
They also have complex, interrelated __________________ that function together
to _____________________________________________________.
1. Body Plan – The body plan of most mollusks has 4 parts:
foot –
different forms:
mantle –
shell –
Has been reduced or lost in:
visceral mass –
2. Feeding
Mollusks can be _______________________________________________________
Snails and slugs feed using a:
Radula –
Octopi and some sea slugs use:
Clams, oyster, and scallops:
Siphon –
3. Respiration
Aquatic mollusks:
Land snails and slugs:
4. Circulation
open circulatory system –
Pathway:
found in:
Faster moving mollusks have:
closed circulatory system –
5. Excretion
6. Response - Varies greatly
Clams and other 2-shelled mollusks:
Octopi and their relatives:
7. Movement
8. Reproduction
Snails and 2-shelled mollusks:
Tentacled mollusks and certain snails:
Some mollusks:
C. Groups of Mollusks
Divided according to characteristics of the ________ and _________
1. Gastropods (Class ________________)
Includes: ________________________________________________________
Gastropods are _____________ or _________________ mollusks that move by
using a ______________________ located on the __________ side.
Snails:
Land slugs and nudibranches:
Some nudibranches:
2. Bivalves (Class _____________)
Bivalves have _______________ that are held together by ______ or _______
_____________________.
Include: _________________________________________________________
3. Cephalopods (Class ________________)
Includes: ________________________________________________________
Cephalopods are typically _________________ mollusks in which the head is
attached to a ________________. The foot is divided into ___________or ______
D. Ecology of Mollusks