Exam 5 Material (Platyalminthes: Type of lophotrochozoa)

Question 1

What do platyalminthes NOT have?

Answer 1

coelom (are triploblastic though) (are called acoelomates)

Question 2

Are platyalminthes a monophyletic group?

Answer 2

They are not necessarily a monophyletic group

Question 3

What kind of symmetry do platyalminthes have?

Answer 3

Bilateral symmetry (b/c of this we often see cephalization/concentration of sensory organs around a head region)

Question 4

How many opening do platyalminthes have?

Answer 4

Only one opening into and out of their digestive tract (one mouth, no anus)

Question 5

What kind of nervous system do platyalminthes have?

Answer 5

lateral-like (at the head they have ganglia, then they have two nerve cords extending down the length of their body—there are nerves going across these nerve cords/makes it look like a ladder)

Question 6

Are tubullaria (type of flatworm/platyalminthes) (includes planarians) parasitic or free-living?

Answer 6

They are free-living

Question 7

What is special about the tubullaria’s mouth?

Answer 7

Its mouth has muscular pharynx (can extend down into a food, allowing the mouth to touch it and then sucks it up its pharnyx and then into its gastrovascular cavity—where digestion happens–increased surface area helps w/ absorbing nutrients)

Question 8

How can tubullarians reproduce?

Answer 8

Sexually and asexually (when they reproduce sexually, they’re homopharidic)

Question 9

Are trematodes/monogeas (types of plathylminthes) parasitic or free-living?

Answer 9

They are parasitic/have hooks for attachment to their host

Question 10

What type of breeders are trematoda/monogenea?

Answer 10

They are proleptic breeders (make lots of babies)

Question 11

Do trematoda/monogenea have alternate generations?

Answer 11

Yes, they have alternate sexual and asexual generations (can have very complicated lifestyles w/ one or more intermittent hosts)

Question 12

Are cestoda (tapeworms/type of flatworm) parasitic or free-living?

Answer 12

Cestoda are parasitic

Question 13

What are the chain of segments on cestoda’s body called?

Answer 13

Proglottids (inside they have both male and female structures and can contain up to 10,000 eggs) (they can have very long/flat bodies w/ a scolex/head, with hooks on it that attach to the intestines of their host)

Question 14

Can cestodas “self” asexual reprodution)?

Answer 14

Some can and some can’t

Question 15

Where will some cestodas release their eggs (while others break off their proglottids and release those in the feces)?

Answer 15

Through the feces of their host

Question 16

Do cestodas have a digestive system?

Answer 16

They have no digestive system of their own OR a mouth (but they have a head) (absorb nutrients from host through their bodies—can have complicated life cycles w/ multiple hosts)