Platytheminthes Flashcards
Description of Platyhelminthes
flatworms
some are terrestrial, others are marine
active
What is bilateral symmetry?
a single plane that you can cut an animal in half to get mirror images
what is bilateral symmetry associated with? why?
cephalization, emergence of heads, needs it to hunt prey and run away to move through space more efficiently
frontal plane
top to bottom
sagittal plane
left to right
transverse plane
anterior to posterior
dorsal
top
anterior
front
ventral
bottom
posterior
back
what is a coelom?
internal body cavity which is an empty space line with mesoderm
what does the mesoderm filled with?
parenchyma: living cells that fill the mesoderm
what is diploblastic and triploblastic?
two layers and three layers
what are platyheminthes
free-living
bright colored, signal toxicity
parasite: tapeworms, suckers & hooks
what are the four classes of platyheminthes?
tubellaria (marine flatworm), trematoa (diagenetic flukes), monogenean (monogentic flukes), Cestoda ( tape worms)
which of the four classes are free living and parasitic?
free living: turbelaaria, everything else parasitic
how to flatworms move?
water flatworms: peristalsis
land flatworms: rhabidites secrete a mucus for the cilia to move or perstalsis
how do flatworms not move
- Dual-gland adhesive organs
- viscid glands secrets liquid
- interacts with oxygen to form a cement like glue
- viscid glands secrets liquid
- Releasing gland
- secretes a liquid to neutralize the glue
How do flatworms eat?
- tubellarians eat with extensible pharnyx
- cestodes eat with out intestines
what is the sub epidermal nerve plexus?
articulated nerve network without a central governing system; controls perstalisis and environement
what do the nerve cords do?
sends signals to the brain to and fro
what is the bilobed ganglion?
specialized bundle of neurons with cell differnation (brain); integration and muscle response
what do the auricles do?
areas of the worms where lots of nerves are concentrated, statocyst, ocelli, rheoreceptors
what do rheoreceptors do?
sensory cells that sees water currents
how do flatworms omosregulate?
- protonephridia cells
- flagella –> weirs (gates that capture fish and filter, exclude large molecules that are needed) –> tubulues –> collecting ducts –> nephiridopores
- flame cell interdigitate with a receiving ce
how do flatworms reproduce asexually
- incredible reproductive bodies
- stems cell that cover the body
- decapitation
- planaria regeneration
- attach to the intestine and attach by placing zooids after their heads
how do flatworms reproduce sexually?
- monoecious
- both organisms get can get pregnant
- cross fertilize
- exchanging of sperm
- more genetic diversity
- rapid population growth
- has become a competition to see which one would become the male and female
- female essentially have the most energy with the children
- biological cost that males do not have
- males trying escape responsibility
- find each other through chemical signals in the slime
endolecithal?
yolk inside the egg
ectolecithal?
yolk surrounds the embryo, basically outside the cell
