L 12 - platyhelminthes & nemertea

Question 1

turbellaria

Answer 1

extensively ciliated, glandular epidermis.

only some show spiral cleavage

Question 2

turb =?

Answer 2

roiling disturbance

cilia cause water to move.

Question 3

Turb =mutliciliated cells produce mucus called?

Answer 3

rhabdites - pocket of mucus. they use this to crawl on, capture prey and copulate

Question 4

turb = how do they alter body shape?

how do they move?

Answer 4

body shape w circular, longitudinal, dorsovental. move w ciliea.

Question 5

NS of turb?

Answer 5

ladder-like NS. distinct anterior ganglion. Main L/R trunks

Question 6

sensory organs present in turb?

Answer 6

eyes - light sensitive

chemoreceptors - detect stuff around you.

Question 7

gut types in turb

Answer 7

simple/sac-like

tricladida (3-branched), polycladid (many branches)

Question 8

where is mouth?

feeding?

Answer 8

mid-ventral, sometimes anterior mouth.
predatory and scavengers = digest externally, secrete enzymes on food, take into gut. branched gut takes nutrients where it needs to go in body.
no anus, regurgitated thru mouth.
some have symbiotic algae

Question 9

repro of turb

Answer 9

hermaphroditic.
fertilziation internal - copulation or traumatic insemination.
produce hard-shelled cocoon around egg.

Question 10

2 groups of yolk placement

Answer 10

1. inside egg cytoplasm = endolecithal = archoophora

2. around outside of egg = lectolectithal = neoophora

Question 11

3 parasitic taxa in platyhelminthes

Answer 11

trematoda
monogenea
cestoda

Question 12

shared traits in 3 parasitic taxa with turb

Answer 12

dorsoventral flat body, blind gut, protonephridia, neoophoran, coputlation

Question 13

differences btw turbellaria and 3 parasitic taxa

Answer 13

eyes (parasitic lack), epidermis has cilia

syncytial epitheliumm - protective from host

Question 14

what is syncytial epithelium

Answer 14

share common cell , membrane lack nuclei

Question 15

more than one intermediate host allows?

Answer 15

enhancement of transmission to definitie host.
simplification via asexual repro.
behaviour of intermediate changed to increaes likelihood of being eaten by final host

Question 16

trematoda

• hosts?
• feeding?

Answer 16

flukes - parasitic. 
typically > 2 hosts. 
oral sucker; 2-branched gut. 
feed by taking tissue into mouths and pumping pharynx. 
definitive host usually verteebrate.

Question 17

CNS in trematods

Answer 17

brain simplified ladder-like NS.

Question 18

KNOW TREMATODE LifE cycLE

Answer 18

draw this

Question 19

cestoda

Answer 19

tapeworms
> 2 hosts. final host = vertebrate.
head = scolex. w hooks and suckers.
no mouth/gut - nutrients taken in by pinacocytes + diffussion. produce segments (proglottids) - packed w fertilized eggs - leave w feces.

Question 20

KNOW CESTODA LIFE CYCLE

Answer 20

draw this

Question 21

phylum nemertea

Answer 21

ribbon worms

- predatory, mostly marine.

Question 22

nemertea - shared traits with flatworms

Answer 22

multiciliated glandular epidermis, protonephridia, ladder-like NS asexual repro + regeneration, spiral cleavage.

Question 23

nemertea - different traits compared to flatworms

Answer 23

body circular, complete gut. closed circulatory system. separate sexes, proboscis in rhynchocoel.

Question 24

how nemertea capture prey

Answer 24

predatory, shoot out proboscis via hydrostatic pressure. proboscis tipped w stylets - punctre prey like harpoon.

Question 25

copulation/repro of nemertea

development post-fertilization

Answer 25

male lack copulatory appendage
extrude egg and sperm simultaneously for external fertilization. sometimes sperm released in mucus on body, swim over to femal and fertilize egg internally.
- development direct or indirect.
- larva pinch off to become juvenile - j eats larva.

Question 26

clade spiralia

Answer 26

spiral cleavage. determinate cleavage (cell X will turn into Y - no other cell will. meaning no twins)

Question 27

platyhelminths AKA =?

phylogeny?

Answer 27

flat worms

unresolved phylogeny; unresolved polytomy

Question 28

platyhelminthes - mode of feeding? habitat?

Answer 28

free-living & parasitic

- marine, freshwater, terrestrial

Question 29

4 major taxa in platyhelminthes

Answer 29

trematoda -parasitic
monogenea -p
cestoda - p
turbellaria - free-living (paraphyletic, group of convenience)

Question 30

platyhelminthes - protostome characters they have

Answer 30

spiral cleavage
blastopore => mouth
multiciliated cells

Question 31

platyhelminthes lack protostome characters:

Answer 31

have blind gut
no circulatory system/coelom
simple ladder like NS , no circumesophageal connectives
excretion by protonephridia (important for osmoregulation)

Question 32

reproduction of platyhelminthes

Answer 32

regeneration & asexual repro = budding, fission, fragmentation.
hermaphroditic - internal fertilization.