Platytheminthes

Question 1

Description of Platyhelminthes

Answer 1

flatworms
some are terrestrial, others are marine
active

Question 2

What is bilateral symmetry?

Answer 2

a single plane that you can cut an animal in half to get mirror images

Question 3

what is bilateral symmetry associated with? why?

Answer 3

cephalization, emergence of heads, needs it to hunt prey and run away to move through space more efficiently

Question 4

frontal plane

Answer 4

top to bottom

Question 5

sagittal plane

Answer 5

left to right

Question 6

transverse plane

Answer 6

anterior to posterior

Question 7

dorsal

Answer 7

top

Question 8

anterior

Answer 8

front

Question 9

ventral

Answer 9

bottom

Question 10

posterior

Answer 10

back

Question 11

what is a coelom?

Answer 11

internal body cavity which is an empty space line with mesoderm

Question 12

what does the mesoderm filled with?

Answer 12

parenchyma: living cells that fill the mesoderm

Question 13

what is diploblastic and triploblastic?

Answer 13

two layers and three layers

Question 14

what are platyheminthes

Answer 14

free-living
bright colored, signal toxicity
parasite: tapeworms, suckers & hooks

Question 15

what are the four classes of platyheminthes?

Answer 15

tubellaria (marine flatworm), trematoa (diagenetic flukes), monogenean (monogentic flukes), Cestoda ( tape worms)

Question 16

which of the four classes are free living and parasitic?

Answer 16

free living: turbelaaria, everything else parasitic

Question 17

how to flatworms move?

Answer 17

water flatworms: peristalsis
land flatworms: rhabidites secrete a mucus for the cilia to move or perstalsis

Question 18

how do flatworms not move

Answer 18

• Dual-gland adhesive organs
  
  • viscid glands secrets liquid
    
    • interacts with oxygen to form a cement like glue
• Releasing gland
  
  • secretes a liquid to neutralize the glue

Question 19

How do flatworms eat?

Answer 19

• tubellarians eat with extensible pharnyx
• cestodes eat with out intestines

Question 20

what is the sub epidermal nerve plexus?

Answer 20

articulated nerve network without a central governing system; controls perstalisis and environement

Question 21

what do the nerve cords do?

Answer 21

sends signals to the brain to and fro

Question 22

what is the bilobed ganglion?

Answer 22

specialized bundle of neurons with cell differnation (brain); integration and muscle response

Question 23

what do the auricles do?

Answer 23

areas of the worms where lots of nerves are concentrated, statocyst, ocelli, rheoreceptors

Question 24

what do rheoreceptors do?

Answer 24

sensory cells that sees water currents

Question 25

how do flatworms omosregulate?

Answer 25

• 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

Question 26

how do flatworms reproduce asexually

Answer 26

• incredible reproductive bodies
  
  • stems cell that cover the body
• decapitation
• planaria regeneration
• attach to the intestine and attach by placing zooids after their heads

Question 27

how do flatworms reproduce sexually?

Answer 27

• 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

Question 28

endolecithal?

Answer 28

yolk inside the egg

Question 29

ectolecithal?

Answer 29

yolk surrounds the embryo, basically outside the cell