Platyhelminthes

Question 1

What is the definition of a platyhelminthes?

Answer 1

A acoelomate triploblast

Question 2

What advent of the platyhelminthes is a common apomorphy across most living thngs

Answer 2

triploblasty

Question 3

What is bilateral symmetry a harbinger of?

Answer 3

directive motion

Question 4

What is undirected swimming

Answer 4

pholagic

Question 5

Define protostomes

Answer 5

The original blastopore is the mouth
Spiral cleavage
Schizocoely

Question 6

Define deuterostomes

Answer 6

The original blastopore is the anus
Radial cleavage
Enterocoley

Question 7

Define Enterocoley

Answer 7

Al little bleb of cell comes off the endoderm, expands, and forms a middle layer called the mesoderm

Question 8

Define Schizocoely

Answer 8

Little bits of mesoderm start near lip of blastopore, and expands filling the space between endoderm and ectoderm

Question 9

Why is the mesoderm important? (3 reasons)

Answer 9

1. Cavity to contain organs in
2. Fluid in mesoderm acts as primitive circulation
3. Ability to move digestive system independently of the body

Question 10

come back to guys who lost the anus

Answer 10

aight

Question 11

What is unusual about he pharynx of the planaria

Answer 11

extends from planaria on the ventral side

Question 12

Define diverticulum

Answer 12

Branches of the digestive system that branch throughout entire body

Question 13

What is unique about the reproduction systems of the planaria

Answer 13

Both female and male parts

Question 14

What happens once the sperm and egg are united in the planaria

Answer 14

The zygote is released out of the planaria

Question 15

What is the skeleton of the planaria filled with

Answer 15

squishy mesophil cells

Question 16

Along with longitudinal muscle, what other muscle groups do planaria have

Answer 16

Dorsoventral muscle

Question 17

Define a rhabdite

Answer 17

Little gnidocyte like cells that eject when the planaria is bitten into the mouth of the predator. Causes bad taste that causes the predator to spit it out.

Question 18

Which side of the planaria is covered with giant cilia

Answer 18

The ventral side

Question 19

Describe planarian nerve system

Answer 19

Two nerve cords that stretch from one end to another, one at either edge of the periphery. The have connectives like ribs connecting them. Congregate near eyespots to form cerebral ganglion.

Question 20

What is the name of the regions sensitive to touch and the presence of certain chemicals.

Answer 20

auricles

Question 21

What was the advantage of the pigmented eye cups?

Answer 21

the planaria can finally orient based on where light is coming from.

Question 22

What is the name of the structure and system that pumps out excess water and waste in the planaria

Answer 22

Protonephrida

Question 23

Describe how the flame cell and tube cell work.

Answer 23

The two cells are partially joined by a lattice work (which is permeable). The flame cell has cilia that propel the liquid and waste down the tube cell and out through the protonephridia.

Question 24

What can most be attributed to the success of the platyhelminthes?

Answer 24

they were parasitic, invading the internal cavities of other animals

Question 25

What is the big secret that allows the planarians to be such good parasites?

Answer 25

they can resist attacks of the immune system

Question 26

How does the syncytial zone of the planarian help it resist immune attacks?

Answer 26

this zone surrounds the entire planarian, one continuous cell. If the immune system breaches one part, you have a continuous massive cell that can quickly bring reinforcements to fix the damage. It also has connexins to cell bodies in the body, so they can also send up reinforcements.

Question 27

How do the microtrix help the planarian evade immune attacks

Answer 27

They snag recognition proteins from the host and affix them to themselves, so that the body thinks they are normal.

Question 28

What is always the intermediate host of the planarian life cycle

Answer 28

the snail

Question 29

what is the miracidium

Answer 29

The free living form of the fluke that seeks to find a snail host and turn into a sporocyst

Question 30

What does the sporocyst in the life cycle of the fluke make?

Answer 30

Redia, which then turn into cercaria

Question 31

What is the goal of the cercaria in the life cycle of the fluke?

Answer 31

To get inside a definitive host, such as a sheep.