Body Plans Flashcards
1
Q
assymetry
A
- no front, no back
- not motile
2
Q
radial symmetry
A
- no front or back
- body parts arranged around a central axis
- e.g. Phyla Porifera, Echinodermata, Cnideria
- sea anenome, starfish, sponges (debatable)
- oral side: where mouth is
- aboral side: side opposite mouth
- not designed to travel any specific direction
3
Q
Radial Symmetry
example
A
4
Q
bilateral symmetry: (numerous phyla)
A
- line down the middle that divides organisms into 2 equal parts
- more or less left & right
- designed to travel forward
5
Q
cephalization
A
collection of sensory neurons at the anterior end of the animal (on nose, eyes, mouth, etc.)
6
Q
Frontal plane
A
Dorsal (top)/ Ventral (bottom)
7
Q
Transverse Plane
A
Anterior/Posterior (comparative)
8
Q
Sagittal Plane (mid-Sagittal)
A
- divides between left & right
- medial: closer to mid-Sagittal plane
- lateral: farther from mid-Sagittal plane
9
Q
To describe location on appendage
A
- Distal: farther from connection point
- Proximal: closer to connective point
10
Q
Diploblastic
A
def: made from 2 layers
- endoderm → lining of digestive tract
- (mesoglea)
- ectoderm → outer covering
Phyla: sponges & sea anenomes
11
Q
Triploblastic
A
made from 3 layers
- endoderm
- mesoglea
- ectoderm
- mesoderm
12
Q
Aceolomate
A
no space between gut & the body wall
13
Q
Pseudocoelomate
A
space between gut & body wall but wall is not mesodermally-derived
14
Q
Coelomate
A
space between gut & wall that is mesodermally derived, i.e. has a coelom.
15
Q
Advantages for coelmate body plan
A
- room for storage of consumed items (food, water)
- room for stored energy
- hydrostatic skeleton – e.g. earthworm – water pressure inside coelom, not crunchy when squeezed
- increase surface area inside/outside organs
- room for muscle contraction
- sum advantage→ increase in size – size matters, bigger you are or appear, fewer things will eat you
