Download Bi 212, Lab 1

Bi 212, Lab 1: Parts to label
1.
Phylum Porifera (Scypha): longitudinal section
a.
ostia (can’t see)
b.
osculum
c.
central cavity (“spongocoel”)
d.
choanocytes
e.
amoebocytes (if seen: could also comment that they are they if you didn’t see them)
f.
collagen (forming amorphic “matrix” of sponge)
2.
Phylum Cnidaria (Hydra): cross section
a.
epidermis derived from ectoderm
b.
gastrodermis derived from endoderm
c.
mesoglia
d.
gastrovascular cavity
e.
cnidocytes (mostly couldn’t see, but should note that they are specialized epidermal cells)
3.
Phylum Platyhelminthes (Planaria): Label both the longitudinal section and the cross
section based on the parts you could see for each. Specific tissue layers best seen in cross-section.
Be sure also to label all places where you have epidermis, mesoderm and gastrodermis (i.e. both
the pharynx and the body itself).
a.
epidermis derived from ectoderm (multiple places in cross-section)
b.
muscles derived from mesoderm (multiple places in cross-section)
c.
gastrodermis derived from endoderm (multiple places in cross-section)
d.
eversible pharynx
e.
mouth (tip of pharynx)
f.
gastrovascular cavity (multiple places in cross-section)
g.
eyespots
h.
auricles
4.
Phylum Nematoda (Ascaris)
a.
cuticle composed of chitin
b.
epidermis derived from ectoderm
c.
longitudinal muscles derived from mesoderm
d.
pseudocoelom (a type of body cavity)
e.
gastrodermis derived from endoderm
f.
intestine (or “digestive tract”)
g.
ovaries
h.
oviducts
i.
uteri (paired)
j.
nerve cord (not always visible)
5.
Phylum Annelida
a.
epidermis derived from ectoderm
b.
circular muscles derived from mesoderm
c.
longitudinal muscles derived from mesoderm
d.
coelom (a type of body cavity)
e.
muscle layer on intestine side of coelom (probably both circular and longitudinal, but
difficult to tell in the cross sections) derived from mesoderm
f.
gastrodermis derived from endoderm
g.
blood vessel (part of its closed circulatory system)