Midterms_Laboratory_Starfish Flashcards
(37 cards)
this is an entire egg that has a rather large prematuration nucleus
unfertilized egg
The nucleus of the unfertilized egg is called?
germinal vesicle
Where is the germinal vesicle located?
Germinal Spot
Function of vitelline membrane?
protection for the yolk
Fertilization membrane function?
prevent polyspermy
the space between the egg and envelope membrane is known as the?
perivitelline space
the starfish egg exemplifies what type of cleavage?
Holoblastic
The resulting cells after cell division are called?
blastomeres
A solid multicellular mass formed as a result of cell proliferation.
Morula
This is the intermediary stage between early cleavage and the final blastula.
morula
The starfish develop a hollow sphere called the?
coeloblastula
The starfish develops a hollow sphere (coeloblastula) containing a fluid in its central cavity known as the?
blastocoel
A layer of peripheral cells, not of uniform thickness, surrounding this cavity is the?
blastoderm
What pole gives rise to the ectoderm and ectodermal derivatives?
animal pole
T or F
The coeloblastula loses its spherical shape and becomes flattened at the animal pole. This flattened part represents the future region of the embryo.
False: animal, vegetal
The center of the flattened part of the coeloblastula invaginated to form a new cavity called?
gastrocoel
What do you call the opening of the archenteron?
gastropore
Gastropore gives rise to the?
anus
At what embryonic stage does the 3 germ layers form?
Gastrulation stage
Locate the mesenchyme cells.
between the ectoderm and gut
free-swimming, bilaterally symmetrical larvae of the starfish.
Bipinnaria
The function of nutritive phagocyte?
The vitellogenic oocyte is surrounded by a mitotic layer called?
germinal epithelium
This is the sac that holds the eggs in place.
gonadal sac
