P H Y L U M P L A T Y H E L M I N T H E S ( F L A T W O R M S ! ) Diana Luo Hong Joo Kim Carrie Yang Period 5 .

PHYL

UM P

LATYH

ELM

INTH

ES

(“FL

AT W

ORM

S!”)

Diana Luo

Hong Joo Kim

Carrie Yang

Period 5

http://clean-water.uwex.edu/pubs/clipart/critters.plan.htm

Hello!

CLASSES OF FLATWORMS (TURBELLARIA)

Most are marine organisms, some are freshwater

All are free-living organisms Feeds on smaller animals, dead animals Dugesia “planarians” (about 4,500 species)

http://www.thaigoodview.com/library/contest2551/science04/119/kingdon_animalia/Class%20Turbellaria.htm

Diana Luo, Hong Joo Kim, Carrie Yang

CLASSES OF FLATWORMS (MONOGENEA)

Marine and freshwater parasites

Most are external parasites of fish

Relatively simple life cycle

Monogeneans (about 1,100 species)

http://simple.wikipedia.org/wiki/Monogenea


CLASSES OF FLATWORMS (TREMATODA)

Suckers for attaching to internal organs or outer surfaces of the host

Many require an intermediate host in which larvae develop

Trematodes, flukes (about 11,000 species)

http://biodidac.bio.uottawa.ca/thumbnails/filedet.htm?File_name=Trem054p&File_type=gif Diana Luo, Hong Joo Kim, Carrie Yang

CLASSES OF FLATWORMS (CESTODA)

Live mostly inside vertebrates & are parasites

Flat, slender, long bodies

Scolex – suckers + hooks

Tapeworms (3,400 species)

http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/Animal%20Diversity/Lophotrochozoans/Lophotrochozoans.htm


BODY SYMMETRY…& BODY CAVITY?

BILATERAL symmetry (identical shape on either side)

Unlike other bilaterians, flatworms do NOT have body cavity between the digestive cavity and outer body wall.

http://www.cartage.org.lb/en/themes/sciences/zoology/biologicaldiverstity/AnimalsI/AnimalsI.htm


NERVOUS SYSTEM

Flatworms have a Central Nervous System (CNS) – the brain and the ventral nerve cords

A pair of ganglia is located at the anterior end

http://www.cartage.org.lb/en/themes/sciences/zoology/biologicaldiverstity/AnimalsI/AnimalsI.htm


SENSORY STRUCTURES/FEATURES Ganglia, or clusters of neurons, present at the anterior

end demonstrates cephalization, trend in which nervous tissue becomes concentrated at one end

A planarian’s head is equipped with a pair of light-sensitive eyespots and lateral flaps that function mainly to detect specific chemicals.

http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb5pg5.htm Diana Luo, Hong Joo Kim, Carrie Yang

CIRCULATORY SYSTEM

They have no organs specialized for circulation A muscular pharynx that leads to the digestive

system is present instead


DIGESTIVE SYSTEM

They have a gastrovascular cavity with only one opening. The many branches of this distribute food throughout the animal


EXCRETORY SYSTEM

They have a excretory system that eliminates nitrogenous waste (ammonia) by diffusion across the body surface.

Simple excretory apparatus (which consists of ciliated cells called flame bulbs that waft fluid through branched ducts opening to the outside) functions to maintain osmotic balance with their surroundings


LOCOMOTION/MUSCULATURE

Glide along surfaces on mucus that they secrete Others use muscles to swim through water with

an undulating motion Planarians move by using cilia on their ventral

epidermis

http://www.deepseaimages.com/dsilibrary/showphoto.php?photo=19535&cat=all&limit=all


SKELETAL TYPE

The interstitial fluid acts as a hydrostatic skeleton – flatworms change the shapes of the fluid-filled compartments to control their overall form and movement

Diana Luo, Hong Joo Kim, Carrie Yanghttp://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb5pg5.htm

REPRODUCTION (METHODS, TYPES)

Triploblastic development (ectoderm, mesoderm, endoderm)

Planarians can reproduce asexually (through regeneration) or sexually

Tapeworms have proglottids that produce thousands of eggs

Copulating mates cross-fertilize

http://www.tutorvista.com/content/science/science-ii/reproduction/asexual-reproduction.php


GAS EXCHANGE (HOW, STRUCTURES)

Flat shape places all the cells close to surrounding water gas exchange by diffusion

No organs are specialized for gas exchange Every cell is able to partake in gas exchange


QUIZ QUESTIONS 1. While of the following have bilateral symmetry?

a. Porifera (Sponges)b. Cnidaria (Jellyfish and Anemones)c. Platyhelminthes (Flatworms)d. Nematoda (Roundworms)

2. What do Annelida (Segmented Worms) have that Platyhelminthes (Flatworms) do not have?a. Bilateral Symmetryb. Body Cavityc. Respiratory Systemd. Nervous System


QUIZ QUESTIONS 3. What do all of the following have in common:

Platyhelminthes (Flatworms), Arthropoda (Insects and Arachnids), Mollusca (Snails, Clams, and Squids), and Echinodermata (Sea Stars and Sea Urchins)a. Segmentationb. Open Circulatory Systemc. Asexual Reproductiond. Organ System

4. What is the main difference between Platyhelminthes (Flatworms) and Nematoda (Roundworms)?a. A respiratory systemb. Symmetryc. Digestive Systemd. Segmentation


QUIZ ANSWERS 1. C and D Explanation: Porifera do not have symmetry and Cnidaria have

radial symmetry. 2. B Explanation: Both have bilateral symmetry and nervous systems

(although their nervous systems slightly differ). Neither has a respiratory system.

3. D Explanation: Only the Arthropoda have segmentation. Only Mollusca

and Arthropoda have open circulatory systems. Mollusca and Arthropoda do not undergo asexual reproduction.

4. C Explanation: Platyhelminthes have gastrovascular cavities while

Nematoda have a separate mouth and anus. Neither have a respiratory system or segmentation. Both have bilateral symmetry.


Interesting videos for further reference: http://www.youtube.com/watch?v=mh2dTIRR

eXU http://www.youtube.com/watch?v=ET1v9-65J

wk

P H Y L U M P L A T Y H E L M I N T H E S ( F L A T W O R M S ! ) Diana Luo Hong Joo Kim Carrie Yang Period 5 .

Documents

carrie yang slide

carrie yang http

nervous system diana

orgwikimonogenea diana

movement diana luo

surroundings diana luo

species http

trem luo