Platyhelminthes Lab - Biology 205

what is cephalization

development of head end

how many embryonic germ layers do platyhelminthes have

3

Is GVC complete or incomplete

incomplete

do platyhelminthes have a coelom?

No, they are acoelomate

are they monoecious or dioecious, and what does it mean

Monoecious: each individual can produce both sperm and egg

State the 3 free living platyhelminthes

Tricladida, Polycladida, and Rhabdocoela

Main identifier(s) of Tricladida

2 eye spots, cylindrical pharynx, 3 branches GVC

What is a pharyngeal pouch?

space that holds pharynx when retracted

What is the space that holds pharynx when retracted

pharyngeal pouch

What are rhabdities

small, dark spots in epidermis that produce mucus

What cells produce mucus in tricaldida

rhabdities

Main identifier(s) of Polycladida

ruffled pharynx, many tiny eyespots, GVC with many branches

Main identifier(s) of Rhabdocoela

bulbous pharynx, sac like GVC (no branches)

What are neodermata?

parasitic flatworms with modified epidermis called tegument

what is a tegument?

type of epidermis in neodermata (parasitic flatworms) that do not have cilia and are fused together

Which platyhelminthes have shell glands

neodermata

What do shell glands do

location where yolk is deposited into a shell with egg, also stores sperm

Give two examples of Trematoda

Fasciola and Echinostoma

Main identifier(s) of Trematoda

Oral and ventral suckers, uterus with shelled eggs

Name the life cycle stages of Fasciola (Trematoda)

egg to miracidium to sporocyst to rediate to 2nd gen rediae to cercaria to immature flukes to adult flukes

What are miracidum

life cycle stage of Fasciola that burrow through skin of snail

What do miracidium develop into

sporocyst

What do sporocysts do

produce many redia through asexual reproduction

What do rediae do

feed on snail tissue, produce 2nd generation of rediae

What do 2nd gen rediae do

produce many cercaria

What do cercaria do

leave the snail, attach to aquatic vegetation

What happens when a mammal eats aquatic vegetation with cercaria

immature flukes are released

What do immature flukes turn into

adult flukes

How are eggs released in the Fasciola (Trematoda) life cycle?

through feces

Main identifier(s) of Cestoda

no GVC, scolex, proglottids

What are sexually mature proglottids

segments with a complete set of male and female reproductive organs

What are gravid proglottids

segments with only female eggs

What is the life cycle of Cestoda

gravid proglottids are released into intestine, release eggs into environment, develops into onchosphere, eats by pig and developed into cysticercus, humans eat and scolex attaches to intestine

What is this, what does it do

miracdium, hatches from egg and burrows inside snail

What is this, what does it do

Rediae, undergoes asexual reproduction in snail digestive gland

What is this, what does it do

Cercaria, free swimming and attach to vegetation