Transcript Chapter 7 - Worms - Fort Thomas Independent Schools

Chapter 34/35 : Worms
I. Body Positions
Dorsal (Back)
Posterior
(Rear)
Anterior
(Head)
Ventral (Belly)
*Bilateral symmetry – cut down middle and both
halves the same
II. Phylum
Platyhelminthes – flat worm
 1.) Planarian – aquatic
 A.
 2 eyespots (sense light)
 Hermaphrodite (male & female)
 Regenerate – regrow missing parts
 Scavenger
II. Phylum : Platyhelminthes
○ 2.) Fluke
 Parasite
 Thick cuticle & suckers
 Hermaphrodite
 Common in Orient, Cuba
 Life cycle with a snail
II. Phylum : Platyhelminthes
○ 3.) Tapeworm
Head contains
suckers scolex
Proglottid – each contains sex
organs (hermaphrodite)
 Passes through feces eaten by pigs or
cows
 Causes organisms to lose nutrients,
weight, weakness
II. Phylum : Nematoda
Nematoda – round worm
 1.) Ascaris
 B.
 Pigs, horses, humans through dirt or
contaminated food
 2.) Hookworms – bore into feet
 Common in south and tropics
 Cause anemia and slows growth
II. Phylum: Nematoda
 3.) Trichina – found in contaminated
pork
 4.) Pin Worms – found in soil
Phylum : Annelida – segmented
worms, earthworm, leech
 C.
II. Phylum : Annelida
○ 1.) Characteristics of Annelida
 Soil or no soil
 Not parasite
 Called tube within a tube
 Fertilize and aerate soil
 Hermaphrodites
II. Phylum: Annelida
○ 2.) External Parts
 Prostomium – lip
 Clitellum – band of reproduction
segments – 32-37
 Setae – bristles on ventral surface
used for clinging
II. Phylum : Annelida
○ 3.) Digestive System
 Pharynx – sucks soil
 To Esophagus then to crop (stores
food)
 To Gizzard (grinds food)
 Through Intestine and out anus
II. Phylum : Annelida
○ 4.) Circulatory System
 Dorsal Blood Vessel – blood flows
through anterior end
 Ventral Blood Vessel – blood from
posterior end
 Aortic Arches – 5 pairs-like heart –
pumps blood
 Closed Circulatory System – blood
remains in tubes
II. Phylum : Annelida
○ 5.) Respiration & Excercretion
 Absorb O2 and releases CO2 through
skin.
 Mucus from skin helps moisten air for
easier respiration. Also slides
through soil better.
 Waste excreted by anus and
nephridia (holes on segments that act
like kidneys- excrete liquid waste)
II. Phylum : Annelida
○ 6.) Nervous System
 Ventral nerve cord (white)
 Sensitive to sound and light
 Brain Tissue
II. Phylum : Annelida
○ 7.) Reproduction
 Hermaphrodite but eggs must be
fertilized by another worm
*Sperm made in testes and stored in
seminal vessicles. Received sperm is
stored in the Seminal Recepticles.
* During Reproduction *
Worms line up upside-down.
 Eggs Released into slime ring around
clitellum.
 Sperm released to fertilize eggs.
 Slime ring slips off to form protective
cocoon for developing young.
