Test 2: Biology 122: Ch 10.3 Three phyla of worms

What class of annelids are polychaetes?

polychaeta

Annelids: ___________ are typically marine, aka bristle worms

polychaetes

What is the word for marine flatworms?

polycladids

What are the classes of platyhelminthes/How many are there?

Turbellaria, Trematoda, Monogenea, Cestoda

Many flatworms can reproduce through regeneration: what is this used as?

a defense mechanism and a way to rapidly increase the number of organisms in a population

Describe the oligochaeta class in annelids:

1. can be marine, freshwater, and/or terrestrial 2. specially adapted for terrestrial lifestyles 3. consume soil, digest organic parts, and eliminate undigested soil 4. Most members are hermaphroditic 5. examples: the palouse earthworm (lives underground and can burrow down to 15 feet)

What are the advantages of annelids having a body cavity?

1. greater flexibility 2. cushioning of internal organs 3. room for internal organ growth

What are the key characteristics of flatworms?

1. invertebrates 2. bilateral symmetry 3. triploblastic 4. acoelomate 5. lack a digestive track 6. over 20,000 species 7. gastrovascular cavity 8. no true body cavity 9. eyespots (these can sense light) 10. sex organs (asexual and sexual--nearly all are hermaphroditic) 11. some are parasites 12. nervous system that resembles a ladder 13. towards the anterior region, there are two simple brain-like structures called ganglia 14. many can reproduce through regeneration

What are the key characteristics of annelids?

1. invertebrates 2. bilateral symmetry 3. triploblastic 4. coelomate 5. protostome 6. segmented bodies (body segments) 7. complete digestive track 8. closed circulatory system 9. body cavity

What are the key characteristics of roundworms (nematodes)?

1. invertebrates 2. bilateral symmetry 3. triploblastic 4. pseudocoelomate 5. Microscopic 6. Ubiquitous 7. complete digestive track 8. no body segments 9. either free living or parasitic 10. many parasitic ones feed on vertebrates 11. body is covered by a tough, nonliving cuticle

Describe the class hirudinea in annelids:

1. marine, freshwater, and terrestrial LEECHES 2. free-living carnivores or blood-sucking parasites on vertebrates 3. leeches have two ventral suckers, one at the anterior end and one at the posterior end, that help them move and attach 4. have special adaptations (razor sharp jaws, anesthetic, and anticoagulant--still used in medicinal practices--their anticoagulants are being reproduced through genetic bioengineering)

What are the functions for locomotion in annelids due to parapodia ?

1. paddle-like for swimming 2. leg-like for walking 3. scoop-like for burrowing

What does primary bilateral symmetry enable?

Enables active, directed movement and is to be the most efficient form of movement

In polychaete (annelids) reproduction, _____________ is theprocess of releasing the posterior end of the body which then forms a head (with no mouth) large eyes, gametes, and a muscular system capable of swimming. The gut deteriorates to make room.

stolonization

In polychaete (annelids) reproduction, _____________ is when sexually mature worms swim to the surface at the same time to release their gametes

swarming

What are cestodes and what are some characteristics?

tape worms (parasitic); they have no digestive system, they rely on the host's digestive tract and absorb pre-digested nutrients

What is an example of a parasitic flatworm?

tapeworm

In some Annelids, such as earthworms, the body cavity is filled with fluid that? Which does what?

the fluid responds to pressure creating a hydrostatic skeleton; Fluid in the cavity circulates nutrients and oxygen while also aiding in waste collection and disposal

What are the function of parapodia in annelids?

they make it hard for predators to swallow them and in some species, they contain venom

How many classes do annelids have? What are they?

three: polychaeta, oligochaeta, hirudinida

What are the three classes of flatworms that are parasitic?

trematoda, monogenea, cestoda (tapeworms)

T/F: Some flatworms are free-living and others are parasitic

true

T/F: Some flatworms have larval life stages

true

T/F: asexual reproduction is common in flatworms

true

T/F: sexual reproduction is typical and nearly all flatworms are monoecious (or hermaphroditic)

true

What are examples of a roundworm?

heart worms, Guinea worm

_______________ is concentrating sense organs in the anterior region of the body

Cephalization

The worm phyla differ from Porifera and Cnidaria in two main evolutionary advances:

1. Cephalization 2. Primary bilateral symmetry

How can nematodes harm humans?

Guinea worm causes guinea worm disease. Named after the Guinea region of Western Africa where this parasite is common. Comes from drinking unclean water with infected daphnia in it. The eggs are swallowed and worms hatch and breed within the human host emerging from the feet and legs.

What is the phylum name for flatworms?

Platyhelminthes

________________ means that the body can be divided along only 1 plane of symmetry

Primary bilateral symmetry

Describe the tube worm in polychaete (annelids)?

Some polychaetes live in tubes. Their parapodia are used for respiration and are adapted to circulate oxygenated water into tight spaces. Tube worms typically have feathery external gills that they can pull into the tube when they sense danger. The structural composition of the tubes have been studied and determined to be a complex matrix of chitin and proteins. It is secreted by the worm itself and grows in size with the worm. The amount of time the worm can safely spend outside of its tube varies by species.

What are Turbellaria's?

a sub-division of Platyhelminthes; aka freshwater flatworms

What are Planarian's?

an example of turbellaria worms; free-living flatworms that live in quiet ponds or bodies of water aka freshwater flatworms

Which worm has bristles?

annelids

What are some examples of polychaetes (annelid class)?

bristle worms, tube worms, bobbit worms, bone-eating zombie worm on whale falls, scale worm,

Annelids have bristles that are called?

chaetae (or sometimes called setae)

What are the importance of annelids in the ecosystem?

earthworms are decomposers, biodiversity of deep sea environments and other habitats, food source

What are some examples of annelids?

earthworms, leeches, polychaetes

T/F: Flatworms have a respiratory system

false

Animalia includes three phyla of worms with separate lineages. What are they?

flatworms, annelids, and roundworms

What class of annelids are leeches?

hirudinea

How can nematodes be used for biology? biological control?

important organism for genetic research; some species can be used commercially for biological control of other species; some used to control dark-winged fungus gnats; some used to control snail populations; many used to control fungus growth

What is an example of a trematode?

liver fluke

What are the largest of the free living flatworms (turbellaria)?

marine flatworms (polycladids)

Most flatworms live in?

marine or freshwater environments, some are terrestrial but limited to moist habitats

The parasitic flatworms, __________ and __________ feed on host cells, cellular debris, and body fluids. __________ typically have 1 host throughout their lifetime. _________ are parasites with 2 or more hosts in their lifetime.

monogeneans and trematodes; monogeneans; trematodes

What is the scientific phylum name for roundworms?

nematodes

______________ aka roundworms, have cylindrical bodies tapered at both ends.

nematodes

What class of annelids are earthworms?

oligochaeta

For turbellaria (fresh water flatworms) respiration is typically achieved through? Because?

osmosis; because they have no respiratory system

In annelids, typically the bristles extend off of the?

parapodia

Most annelids have ________ which are fleshy appendages that are paired on the segments of the worm

parapodia

Annelids display a key evolutionary adaptation: ______________

segmentation.

In turbellaria, their bodies have a __________ opening

single