Introduction to Development (part 2) Flashcards
begins when a group of cells on the dorsal side of the blastula begins to invaginate
frog gastrulation
part above the crease is called
dorsal lip of the blastopore
cells continue to move from the embryo surface into the embryo by _
involution
cells that move through involution becomes
endoderm and mesoderm
cells on the embryo surface becomes
ectoderm
True or False: Human eggs have large yolks
False;
very little yolk
human equivalent of the blastula
blastocyst
cluster of cells at one end of the blastocyst
inner cell mass
outer epithelial layer of the blastocyst and does not contribute to the embryo, but instead initiates implantation
trophoblast
following implantation, the trophoblast continues to expand and a set of _ is formed
extraembryonic membranes
involves the inward movement from the epiblast, through a primitive streak, similar to the chick embryo
Gastrulation
protects the embryo from dessication and allows reproduction on dry land
amnion
mammals and reptiles including birds are called _ for the reason of having amnions
amniotes
four extraembryonic membranes that form around the embryo
chorion
amnion
yolk sac
allantois
extraembryonic membrane that functions in gas exchange
chorion
extraembryonic membrane that encloses the amniotic fluid
amnion
extraembryonic membrane that encloses the yolk
yolk sac
extraembryonic membrane that disposes of waste products and contributes to gas exchange
allantois
various regions of the germ layers develop into rudimentary organs
organogenesis
In early vertebrate organogenesis, the _ forms from mesoderm, and the _ forms from ectoderm
notochord - mesoderm
neural plate - ectoderm
neural plate curves inward forming the _
neural tube
neural tube becomes the _
CNS (brain and spinal cord)
develop along the neural tube of vertebrates and form various parts of the embryo such nerves, parts of teeth, skull bones and so on.
neural crest cells
mesoderm lateral to the notochord forms blocks called
somites
lateral to the somites, the mesoderm splits to form the
coelom (body cavity)
True or False: Morphogenesis in animals but not plants involve movement of cells
True
promotes elongation of the anchenteron in the sea urchin embryo
cytoskeleton
rearrangement of cells of a tissue that cause it to become narrower (converge) and longer (extend)
convergent extension
programmed cell death
apoptosis
term used to describe the process by which a cell or group of cells becomes committed to a particular fate
determination
refers to the resulting specialization in structure and function
differentiation
True or False: Different cell types is the result of the expression of different sets of genes, thus cells multicellular organisms share the same genome
True
diagrams showing organs and other structures that arise from each region of an embryo
fate maps
specialized cells that give rise to sperm or eggs
germ cells
complexes of RNA and protein are involved in specification of germ cell fate, in C. elegans, such complexes are called _, which persist throughout development, and can be detected in germ cells of the adult worm
P granules
exhibits assymetry across the dorsal-ventral and anterior-posterior axes
bilateral symmetry
What type of axis is largely symmetrical?
right-left axis
When is the anterior-posterior of the frog embryo determined?
oogenesis
indicates where the anterior-posterior axis forms
animal-vegetal
The dorsal-ventral axis is not determined until _
fertilization
performed experiments to determine a cell’s developmental potential
Hans Spemann
affected by distribution of determinants and the pattern of cleavage
Embryonic fates
first two blastomeres of the frog embryo are _, which means it can develop into all the possible cell types
totipotent
In mammals, emrbyonic cells remain totipotent until the _, much longer than other organisms
8 cell stage
tissue-specific fates of cells are fixed by
late gastrula stage
As embryonic cells acquire distinct fates, they influence each other’s fates by _
induction
transplanted tissues between early gastrulas and found that the transplanted dorsal lip triggered a second gastrulation in the host
Spemann and Mangold
functions as an organizer of the embryo body plan, inducing changes in surrounding tissues to form notochord, neural tube, and so on
dorsal lip
molecular cues that control pattern formation are called
positional information
information that tells a cell where it is with respect to the body axes
positional information
determines how the cell and its descendants respond to future molecular signs
positional information
The wings and legs of chicks, like all vertebrate limbs, begins as bumps of tissue called
limb buds
The embryonic cells in a limb bud respond to positional information indicating location along three axes namely:
proximal-distal axis
anterior-posterior axis
dorsal-ventral axis
limb-bud regulating region that is thickened ectoderm at the bud’s tip
Apical Ectodermal ridge
second region and is mesodermal tissue under the ectoderm where the posterior side of the bud is attached to the body
Zone of Polarizing activity
essential for proper specification of cell fate in the human embryo
ciliary function
play roles in left-right specification
motile cilia
play roles in normal kidney development
monocilia (nonmotile cilia)
