Platyhelminthes and Bryozoans Flashcards Preview

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Flashcards in Platyhelminthes and Bryozoans Deck (47)
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1

What evolutionary adaptation do the Phyla Platyhelminthes and Bryozoa have?

Lophophore or Trocophore larva

2

Give the Taxonomy of Platyhelminthes.

Kingdom: Animalia
Clade: Bilateria - Protosmia
Superphylum: Lophotrochozoa
Phylum: Platyhelminthes (flatworms)

3

What kind of Symmetry does Platyhelminthes exhibit?

First appearance of Bilateral symmetry

4

What is significant about the nervous system of Platyhelminthes?

Evolution of Cephalization

5

How many germ layers does Platyhelminthes have?

3 Germ Layers: Endoderm, Ectoderm, Mesoderm

6

Does Platyhelminthes have a Coelem?

No. Just a gut lumen (cavity)

7

What is the parenchyma?

Mesodermal cells that fill the space between gut and ectoderm

8

What advances did the Platyhelminthes make evolutionarily?

Nervous coordination and appearance of an excretory system

9

What kind of body plan do Platyhelminthes have?

Acoelomate Body Plan
-Gut lumen and two intestines (one on each side) running the length of the body
-Mesodermally derived Parenchyma fills up all other space between endoderm and epithilium
-The Pharynx (mouth) is in the center of the body

10

What Organ Systems does the Platyhelminthes have?

-Pharynx and intestine, no anus
-Nervous system connected to brain, Cerebral Ganglia
-Excretory System with flame cells
-Advanced reproductive system

11

Explain the excretory system of Platyhelminthes.

Uses Flame Cells
-Cilia within flame cells beat back and forth (Pressure gradient)
-Causes water to come in through openings
-Water absorbs solutes
-Excess water and waste exit body through protonephridia

12

Is excretion pooping? What is it?

Excretion is not pooping. It is osmoregulation and the elimination of nitrogenous wastes.

13

What are the two types of parasites?

Ectoparasites - outside the body

Endoparasites - in the gut lumen or in bloodstream

14

What are the life stages of parasites?

Adult: lives in final host, uses sexual reproduction

Larva: lives in intermediate host
-Can be active or encysted
-If active, larva may use asexual reproduction

15

How do parasites make up for complex life history and low probability of survival?

Gigantic reproductive effort (asexual or sexual)

16

How do parasites evolve over time?

Tend to evolve to become more "perfect."
-Having less of an effect on host
-Converges toward similar life-history and body plan as host

17

What are the types of symbioses?

Symbiosis - Living together
-Mutualism: both benefit
-Commensalism: one benefits and other unaffected
-Parasitism: one benefits and other harmed

18

How are Platyhelminthes modified for parasitism?

Tegument
-modified epidermis that protects parasite from host and absorbs nutrition

Hooks and Suckers

19

What is the life history of the Class Trematoda (flukes) of Phylum Platyhelminthes?

-Adult Fluke lives in human liver
-Human poops out eggs which end up in water
-Snails eat poop and ingest eggs
-Eggs hatch and miracidium turns into redia in snail
-Redia leaves snail as Cercaria which is eaten by fish
-lives in fish muscle as cyst
-Fish is eaten by human

20

What is the life history of the Class Cestoda (tapeworms) of Phylum Platyhelminthes?

Tapeworms live in human intestine
-Humans poop on grass or open area
-larva in poop eaten by cow
-larva live in cow as cysts in the muscle
-undercooked cow meat eaten by humans

21

How can we prevent Platyhelminth parasites?

1. Use toilet with primary sewage treatment
-prevents eggs from reaching intermediate host
2. Cook food thoroughly
-kills the larval cyst living in the intermediate host
3. Drain pond and kill snails
-kills important intermediate host (disrupts ecology)

22

How many germ layers does Phyla Platyhelminthes have?

Triploblastic - ectoderm, endoderm, mesoderm

23

Is Platyhelminthes protostome or deuterostome?

Protostome

24

What is the habitat that platyhelminthes lives in?

Marine, freshwater, and terrestrial

25

Does Platyhelminthes have a skeletal system?

No

26

How does Platyhelminthes feed?

Free living species feeds using gut

Parasitic species feed using tegument

27

How do Platyhelminthes move?

Gliding on cilia and mucus

28

What is the circulatory system of Platyhelminthes?

No circulatory system. Uses diffusion.

29

What is the mode of excretion for Platyhelminthes?

Protonephridia with flame cells

30

What are the modes of reproduction used by Platyhelminthes?

Sexual and asexual