Zoology Platyhelminthes, Annelida, Nematoda, Mollusca

In Greek, this means flat

Platy

In Greek, this means worm

Helmins

True/False

All creatures under phylum platyhelminthes are parasites

False

This is an organism that lives on or inside another organism, known as the host, from which it obtains nutrients and shelter at the host's expense.

Parasite

This refers to an organism that lives independently rather than as a parasite or a symbiont, obtaining its nutrients from the environment without relying on a specific host for survival.

Free-living organism

80% of platyhelminthes are what?

Parasites

In terms of tissues, organisms under phylum platyhelminthes are what?

Eumetazoans

This refers to an organism with 3 germ layers

Tripoblastic

How many germ layers do organisms under phylum platyhelminthes have?

Three

What are the 3 germ layers?

Ectoderm, Mesoderm, Endoderm

In terms of body cavity formation, organisms under phylum platyhelminthes are what?

Acoelomate

Symmetry of organisms under phylum platyhelminthes

Bilateral Symmetry

These serve as the nervous system of organisms under phylum platyhelminthes

Paired Nerve Cords

This is a dense cluster of nerve cell bodies located outside the Central Nervous System that acts as a relay station or a localized processing center for nerve impulses.

Ganglion

In terms of cephalization, organisms under phylum platyhelminthes are what?

Cephalized

True/False

Organisms under the phylum platyhelminthes have complete digestive systems

False

True/False

Organisms under the phylum platyhelminthes have only one passageway that serves as the mouth and the an*s

True

Organisms under the phylum platyhelminthes have a proper circulatory system

False

Organisms under the phylum platyhelminthes respire through what process?

Diffusion

These are specialized excretory cells found in the simplest freshwater invertebrates, such as flatworms, that function like a primitive kidney.

Flame Cells

These are the network of tubules throughout the body of organisms under phylum platyhelminthes with openings to the environment

Protonephridia

True/False

Organisms under phylum platyhelminthes only reproduce asexually

False

S*xual reproduction of organisms under phylum platyhelminthes

Cross-fertilization

Asexual reproduction of organisms under phylum platyhelminthes

Fission and Regeneration

This is a biological process where the male gamete from one individual fertilizes the female gamete of a different individual of the same species.

Cross-fertilization

This is the passive movement of particles rom an area of higher concentration to an area of lower concentration.

Diffusion

This is a deliberate, proactive method of asexual reproduction where an organism intentionally splits itself into two to increase the population.

Fission

This is a form of asexual reproduction where an organism breaks into several pieces, and each fragment uses its inherent power of regeneration to grow into a new, complete individual.

Fragmentation/Regeneration

This refers to a biological system where a single individual possesses both male and female reproductive organs, allowing it to produce both types of gametes.

Monoecious

True/False

All organisms under phylum platyhelminthes are monoecious

False

What are the 4 classes under phylum platyhelminthes?

Turbellaria, Monogena, Trematoda, Cestoda

This is the only class under phylum platyhelminthes that is free-living

Turbellaria

Other name for Class Turbellaria

Free-Living Planarians

Free-living planarians have a protrusible or retractable ________

Pharynx

This is the chemosensory protrusion of free-living planarians

Auricle

These are the light-sensitive organs of free-living planarians

Eyespots

This refers to the intestinal trunk of free-living planarians

Gastrovascular Cavity

What are the 2 types of parasitic flatworms?

Ectoparasite and Endoparasite

An ectoparasitic flatworm which consists of small, flat parasites that live on the external surfaces of aquatic hosts, such as the gills, skin, or fins of fish.

Class Monogenea

These are organisms that live on the external surface of their host, such as the skin or gills, to feed on blood or tissue.

Ectoparasites

These are organisms that live inside the host's body, inhabiting areas like the digestive tract, lungs, or bloodstream.

Endoparasites

These are the parasites that transmit zoonotic diseases

Endoparasites

These refer to diseases that can be transmitted from animals to humans and vice versa

Zoonotic Diseases

This refers to a host species that only harbors the immature parasite

Immediate Host

This refers to the host species that harbors the sexually mature parasite

Definitive Host

Gyrodactylus elegans belongs to what class?

Class Monogenea

Monogenean Ectoparasites are usually found on what part of the host’s body?

Skin

Monogenean Endoparasites are usually found on what part of the host’s body?

Cloaca or Bladder/Not too deep in host tissue

Usual hosts for monogeneans

Fish

These are muscular, cup-like structures that use negative pressure to adhere to the smooth surfaces or soft tissues of a host.

Suckers

These are complex, often sclerotized mechanical structures used by certain ectoparasites to pinch and firmly grip host tissues like gill lamellae.

Clamps

These are sharp, curved "anchors" that pierce and lock into the host's skin or intestinal lining to prevent the parasite from being dislodged.

Hooks

These are small, needle-like projections covering the body or specific organs that provide friction and help the parasite burrow into or maintain its position within host tissues.

Spines

These are specialized biological structures that allow organisms, particularly parasites, to stay anchored to their host or substrate to prevent being dislodged by movement, fluids, or gravity.

Attachment Organs

This is the specialized posterior attachment organ found in monogenean flatworms, used to anchor the parasite to the external surfaces of its host, such as fish gills or skin.

Opisthaptor

Dactylogyrus spp. Class

Monogenea

Class Trematoda usually consist of what type of parasites?

Endoparasites

Other name for organisms under class Trematoda

Flukes

Schistosoma belongs to what class?

Trematoda

What disease is caused by the Schistosoma spp.?

Schistosomiasis/Bilharziasis/Snail Fever/Disease of Poverty

This is the most common parasitic infection to humans next to malaria

Schistosomiasis

True/False

Schistosomiasis is very common in Samar and Leyte

True

What is the usual attachment organ for organsims under class Trematoda?

Sucker

When penetrating into host tissue, what body part is left by a parasite under class trematoda?

Tail/Furca

What is the infective stage of Schistosoma?

Cercaria

This refers to the tail that is left when organisms under class trematoda penetrates host tissues

Furca

What is the only part of trematodes that penetrates skin?

Cercarial Body

Schistosoma japonicum belongs to what class?

Trematoda

Schistosoma malayensi belongs to what class?

Trematoda

Schistosoma intercalasi belongs to what class?

Trematoda

Intermediate host of Schistosoma spp.

Oncomelania quadrasi

Definitive host of Schistosoma spp.

Humans

This is known as the common liver fluke

Fasciola hepatica

This is known as the giant liver fluke

Fasciola gigantica

Infective stage of flukes

Metacircariae

Intermediate hosts of flukes

Limnea sp. and plants

This is known as the Chinese Liver Fluke

Chlonirchis sinensis

Intermediate host of Chlonirchis sinensis

Carp/Cyperinidae Family

This refers to the swimming larvae of trematodes

Cercaria

This is known as the lung fluke

Paragonimus wertermani

What disease is caused by lung flukes?

Paragonimiasis

Intermediate host of lung flukes

Freshwater snails and crustaceans

Tapeworms belong in the class

Cestoda

Attachment organs of cestodes

Suckers and Hooks

This is the specialized "head" or anterior attachment organ of a tapeworm that is equipped with suckers, hooks, or grooves to anchor the parasite to the intestinal wall of its host.

Scolex

This is a retractable, fleshy, cone-like projection located at the very tip of the scolex of certain tapeworms, often functioning as a platform for a circular "crown" of sharp hooks.

Rostellum

These are the individual, box-like segments that make up the long, ribbon-like body of a tapeworm, each functioning as a complete, self-contained reproductive unit.

Proglottids

This refers to a chain of proglottids

Strobila

Three types of proglottids

Immature, Mature, and Gravid Proglottids

These are the youngest proglottids located nearest the neck, characterized by their small size and the presence of developing, but not yet functional, reproductive organs.

Immature Proglottids

These proglottids are found in the middle of the body and contain fully developed, functional sets of both male and female reproductive systems ready for fertilization.

Mature Proglottids

These proglottids are the oldest segments at the posterior end of the worm, which consist almost entirely of an expanded uterus filled with thousands of fertilized eggs.

Gravid Proglottids

True/False

Tapeworms have digestive tracts

False

Larval stage of tapeworms

Cysticerci (Plural), Cysticercus (Singular)

Tapeworms acquired when eating improperly prepared pork

Taenia solium

Tapeworms acquired when eating improperly prepared beef

Taenia saginata

Taenia sp. only found in the Asian continent

Taenia asiatica

True/False

Taenia solium can be found anywhere in the body

True

True/False

Taenia saginata can only be found in the gastrointestinal tract

True

Disease caused by Taenia sp.

Taeniasis