5.2.4. Platyhelminthes

Question 1

Phylum Platyhelminthes (Flatworms)

\_\_\_\_ symmetry
\_\_\_\_\_ – Lack a body cavity(coelom)
3 Layers : endoderm, ectoderm, mesoderm
Gastrovascular cavity
Mouth – one opening
\_\_\_\_\_\_-nerves and sense organs at anterior end

Answer 1

Bilateral
Acoelomate
Cephalization

Question 2

Includes marine worms & planarians

*Most free living

Answer 2

Class Turbellaria

Question 3

PLANARIAN

Movement: \_\_\_ on ventral surface/ muscle contractions
Digestive System:
• Feeding: \_\_\_\_\_(middle of body)
• Gastrovascular cavity
No Respiratory/ Circulatory system: \_\_\_\_
Nervous System:
• \_\_\_\_ (simple brain) , 2 Nerve cords.
Eyespot(senses light)

Answer 3

cilia
suction of pharynx
diffusion
Ganglia

Question 4

Planarian

Excretory System:
• \_\_\_\_\_- remove fluid waste
Reproduction:
• Sexual- h\_\_\_\_, cross fertilize
• Asexual- \_\_\_\_

Answer 4

Flame cells
hermaphrodite
regeneration

Question 5

-flukes (parasitic)
• Leaf-shaped
• Sucks blood, cell fluids

Answer 5

Class Trematoda

Question 6

Blood fluke ____ causes disease _____

Answer 6

Schistosoma; Schistosomiasis

Question 7

• Tapeworm
• Parasite
Body: absorbs nutrients; tegument/cuticle prevents parasite from being digested by host

Answer 7

Class Cestoda

Question 8

____- hooks and suckers that attach to intestinal wall (no mouth)
_____- segment containing reproductive organs

Answer 8

Scolex

Proglottid

Question 9

Prevention of having tapeworms (3):

Answer 9

Worm livestock

USDA inspection

Cook meat