bilateria

Question 1

features uniting bilateria

Answer 1

1. bilateral symmetry
2. cephalization
3. mesodermally derived tissue

Question 2

what is cephalization?

Answer 2

concentration of sense organs and NS at anterior end.

Question 3

mesodermally derived tissue - what does that mean for tissue?
soft- bodied forms have what kind of body wall muscles

Answer 3

triploblastic -

- circular and longitudinal body wall muscles.

Question 4

3 planes of bilaterally symmetrical organisms

Answer 4

transverse
frontal
sagital

Question 5

common features of bilaterians

Answer 5

internal fluid transport system
 - most have 2
complete through-gut w mouth and anal opening. 
excretory organs
1/2 forms of nephridial systems

Question 6

fluid filled transport system

Answer 6

fluid-filled cavities flly enclosed + under control of organism

Question 7

2 types of fluid filled systems usually found in fluid-filled systems

Answer 7

1. spaceous

2. blood-vascular system

Question 8

3 steps for excretion

Answer 8

1. ultrafiltration
2. resorption
3. transport out.

Question 9

2 forms of nephridia systems

Answer 9

1. metanephridia - usually large animals w blood vascular system. filtration in structure separate from resorption/transport.
2. protonephridia - small animals, lack coelom. all 3 steps occur in one structure.

Question 10

difference btw smal & large eating habits.

Answer 10

small = extrude mouth as solid gut mass, surround food and bring it back in. 
large = grasp prey w anterior part of body. immobilizes w / mucuous and injest