Biology Chapter 25 worms and mollusks

What is the Phylum name for Flatworms?

Platyhelminthes

How many species are in the Phylum Platyhelminthes?

20,000

What is the Phylum name for Flatworms?

Platyhelminthes

How many species are in the Phylum Platyhelminthes?

20,000

Where do Flatworms live?

Free living in aquatic or terrestrial

How long do Flatworms get?

1mm to many meters long

What type of symmetry do Flatworms have?

Bilateral symmetry

what does a Flatworm look like?

thin, flat body

What do Flatworms eat?

Dead or slow moving organisms

What is a pharynx?

tubelike muscular organ is extended out of their mouths and releases enzymes that start digesting the prey.

where is waste ejected from?

The mouth

What helps parasitic Flatworms hold on to there host?

Hooks and Suckers

How do Flatworms eat?

Either through their body walls or through there pharynx

Are Flat worms coelomates,Acoelomate,or psuedocoelomate?

Acoelomate

What makes up the excretory system in Flatworms?

networks of tubules and ciliated flame cells

What is a flame cell?

The flame cells sweep water and excretory substances into the tubules, which then release it from the body through pores

how many nerve chords does Flatworms have?

Two nerve cells that resembles rung of a ladder

What are Cerebral Ganglia in Flatworms?

a group nerve cells that function as a simple brain

How do Flatworms move?

contracting muscles, but most move using cilia on their undersides

How do Flatworms reproduce?

Flatworms are hermaphrodites that reproduce sexually with internal fertilization or they reproduce a sexually by regeneration

What are the three classes of Flatworms

Turbellaria, Trematoda, and Cestoda

What are Turbellaria?

a type of Flatworm which live in freshwater and marine environments, and in moist soil.  They have eyespots that can detect light.  The auricles on the sides of the head are used to detect chemical stimuli coming from food.

What are Trematoda?

a type of Flatworm which are parasites that infect the blood or organs of their hosts.

What are Cestoda?

a type of Flatworm which are parasites adapted to living in the intestines of their host.  The scolex is structure with hooks an suckers that help the tapeworm attach to the wall of its host’s intestine. Sections after the scolex are called proglottids involved in nutrient absorption and reproduction

What Phylum are Roundworms?

Phylum Nematoda

Are Roundworms coelomates,Acoelomate,or psuedocoelomate?

They are pseudocoelomates and have a fluid-filled body cavity partially lined by mesoderm

What type of symmetry does round worms have?

they have bilateral symmetry, are cylindrical, unsegmented, and tapered at both end

How long are Roundworms?

1mm to 9 meters long

Where do round worms live?

marine, freshwater, and terrestrial environments

What is the Phylum of Rotifers?

Phylum Rotifera

How long are Rotifers?

0.1 to 0.5 mm in length

How many species are in Phylum Rotifera?

1,800

Where do Rotifers live?

Freshwater habitats

What type of symmetry do Rotifers have?

Bilateral symmetry

Are Rotifers coelomates,Acoelomate,or psuedocoelomate?

Psuedocoelomate

How do Rotifers move?

They move through the water by means of ciliated wheel-like structures and posterior ends has “toes” that anchor the rotifer to underwater surfaces

How do Rotifers eat?

Feed by using cilia to gather protists and other organic material

What is the Phylum of Rotifers?

Phylum Mollusca

How many species are in Phylum Mollusk?

over 110,000

Are Mollusk coelomates,Acoelomate,or psuedocoelomate?

coelomates

Where do Rotifers live?

many are marine, some are freshwater, and some are land

What were Mollusk most likely the first animal to have developed?

Protostome development

What type of symmetry do Mollusk have?

Bilateral symmetry

How do mollusk move around?

Foot. The muscular foot of mollusks like snails and bivalves is used for movement through the environment or jet propulsion

What is the membrane that surrounds the internal organs called?

Mantle

What is secreted to form shells?

Calcium Carbonate

Do all Mollusk have shells

No, some like squids, octopuses, cuttlefish, nudibranchs, and slugs do not have hard external shells

What is the rasping structure meant mollusk have and do?

A radula is a tonguelike organ with rows of teeth to scrape food into their mouths

how do Mollusks eat?

Herbivorous mollusks scrape algae with their radulae, carnivorous mollusks use theirs to drill into other mollusks by using their radula. Clams and mussels (bivalves) are filter feeders and do not have radulae

How do marine Mollusks breath?

Gills are a system of filamentous projections rich in blood supply for bringing in oxygen to the body and removing carbon dioxide

How do land and some freshwater Mollusk breath?

by the use of the lining of their mantle cavities to take in oxygen from the air

Mollusk have what kind of well developed system?

circulatory systems, including a chambered heart

What kind of circulatory system do most Mollusk have?

Most have an open circulatory system in which blood is pumped out of blood vessels into open spaces surrounding body organs

How do Mollusk excrete metabolic waste?

Nephridia by they filter the blood and move wastes out through the mantle cavity

What does the nervous system do Mollusk have?

coordinate their movement and behavior

How do Mollusks reproduce?

Mollusks reproduce sexually. Many mollusks release eggs and sperm into water for fertilization. Some bivalves and many snails have internal fertilization

What classes are in the Phylum Mollusca

Gastropoda, Bivalvia, and Cephalopoda

What is Class Gastropoda

“stomach foot” – largest class of mollusks including one-shelled snails, conches, periwinkles, limpets, cowries, whelks, and coneshells and non-shelled slugs and nudibranchs

What is class Bivalvia?

two-shelled mollusks including clams, mussels, oysters, and scallops

what is class Cephalopoda?

“head-footed” – fast-moving, intelligent, include squid, octopus, chambered nautilus, and cuttlefish. All except the nautilus lack external shells but they can move quickly and excrete a cloud of ink to scare away predators and use camouflage