Bilateria (Animals with Bilateral Symmetry)

Question 1

bilateria

Answer 1

• bilateral symmetry
• dorsal and ventral sides
• cephalization
• filtration excretory organs

Question 2

cephalization

Answer 2

evolutionary trend - nervous tissue over many generations becomes concentration toward one end of an organism

Question 3

protosotmia

Answer 3

w/in bilateria

• blastopore (mouth)
• schizocoely (body cavity formed by splitting the mesodermal embryonic tissue)

Question 4

spiralia (lophotrochozoa)

Answer 4

w/in protosotmia
annelids, mollusks, bryozoans, chaetogaths, rotifers
- larval protonephridia
- chaetae (stiff bristles)
- beta chitin

Question 5

ecdysozoa

Answer 5

w/in protosotmia, moulting animals (arthropods, nematodes)

Question 6

protonephridia

Answer 6

flame cell - create a vacuum that sucks out substances on the other side of a membrane (filters)

Question 7

platyhelminthes

Answer 7

w/in spiralia
flatworms!
- multi-ciliated epidermis and gastrodermis
- two cilia per protonephridial terminal cell

Question 8

Turbellaria

Answer 8

NOT AN ACCEPTED GROUP
diverse, free-living, no cuticle
- circular, longitudinal and dorsoventral muscle
- mouth, but NO POO HOLE

Question 9

rhabdites

Answer 9

• rod-shaped secretions from the cell wall
• recreated by epidermal glands
• slime production
• in turbellaria

Question 10

statocysts

Answer 10

gravity recptor

Question 11

ciliary receptors

Answer 11

mechanoreceptor - mechangical pressure or distorition

Question 12

chemoreceptors

Answer 12

detects chemical stimuli in the environment