Module 2: Quizzes Flashcards
T/F Until the blastula stage, the cleavage stage embryo relies on maternally
deposited mRNA and proteins.
T
T/F If action polymerization is blocked using a drug, cortical rotation will not occur
and therefore Nieuwkoop center is not formed.
T
T/F Lithium blocks cortical rotation and blocks siamois expression
F
- Lithium inhibits GSK3
T/F The normal fate of dorsal mesodermal cells is to differentiate into muscle and
notochord
T
T/F Type I TGFb-receptor phosphorylates Smad 2/3
F
Type II must first phosphorylate Type I then Smad 2,3 can be phosphorylated
T/F b-catenin and Vegt bind to the enhancer of nodal and control the gene
expression
T
T/F GSK3 is the critical component that is transported to the dorsal side of frog
embryo after cortical rotation?
F
In Xenopus, the mesoderm moves in through the blastopore by rolling around the dorsal lip. This process is called:_________________
Involution
In Xenopus, the organizer mesodermal cells undergo intercalation and the tissue
elongates toward the anterior region. This process is called: _____________
Convergent Extention
What is the name of the first visible structure that forms at the beginning of neurulation? _________________
Neural plate
T/F: Notochord originates from the chordamesoderm and is the most anterior mesoderm structure in vertebrates
F
- It is the POSTERIOR
Identify three factors that are secreted from the organizer.
BMP - ventralization
Noggin, Chordin, and Follistatin secreted dorsally to inhibit BMP
Describe the common neural induction mechanism that is shared between Xenopus and Drosophila.
- BMP is like Dpp, Chordin is like Sog
- Lack of BMP/Dpp is required for neuralization
- Chordin and Sog secreted into neuroectoderm to create BMP/Dpp inhibition
What molecules are emitted from the mesoderm to induce posterior neural tissues?
Wnt and retinoic acid
____________ cells converge on the streak, and as it moves forward, prospective
mesoderm and endoderm cells move inward, spreading anteriorly and laterally, to form the ___________ layer
Epiblast, Mesenchymal
The primitive streak of chick embryos is equivalent to which amphibian structure?
Blastopore
The ___________ in the early chick embryo is a sheet of cells that give rise to
extraembryonic structures
Hypoblast
How long does it take for a chick embryo to reach gastrulation? How many days does it take for a chicken embryo to hatch?
24 hours, 20 days
Identify two secreted molecules that are expressed in Koller’s sickle.
Vg1 and Wnt
A
T/F: Presomitic mesoderm forms between the regressing Hensen’s node and the last
formed somite.
T
T/F: Presomitic mesoderm acquires an anteroposterior positional identity before somite formation.
T
T/F: If an extra piece of notochord is transplanted into a dorsal position adjacent to pre-somitic mesoderm, the somite will be converted almost entirely to muscle-forming cells
F
- it will become an induced axis
The dermomyotome gives rise to two important structures. What are they?
________________ and ____________
Dermis and myotome
When does the mediolateral patterning of somites occur in development?
a) Before neurulation
b) During neurulation
c) After neurulation
C
Name a signal that is emitted by notochord and affects sclerotome development.
____________
Sonic hedgehog
What molecules are involved in segregating each rhombomere to avoid cell mixing?
_______________ and ________________
ephrin, EPH
Where do you initially see the primitive streak in the mouse embryo? What does it do?
- Beginning of Gastrulation
- Forms Epiblast
- signals start of gastrulation
- Starts at caudal and moves anteriorly making notochord
What is a blastocyst?
-Structure formed in early mammal embryogenesis
- Consist of two cell types; inner cell mass and trophectoderm (outer layer cells)
What day does a blastocyst form in mice?
Day 3.5
In mouse embryos, which of the following tissue will give rise to the embryo proper?
a) epiblast
b) inner cell mass
c) primitive endoderm
d) a and b
e) a, b and c
D
- Both Epiblast and inner cell mass result in the embryo proper (Blue on chart)
Cite two reasons why you wish to insert a drug resistant gene in the exon of a gene you
wish to knockout in ES cells
- inactivate target gene where drug selectable marker is inserted
- enable selection of cells that have corrected DNA insertion
T/F. Most people with situs inversus have no medical symptoms or complications
F
T/F. Asymmetric activity of a proton potassium ATPase pump is one of the earliest signs
of LR asymmetry in chick.
T
T/F In mammals, motile cilia produce a leftward flow of extraembryonic fluid and
eventually, this results in increasing Nodal production on the left.
T
How would you identify patients with situs abnormality?
radiography, ultrasound,CT scan
T/F. The general cell movement during gastrulation is similar in avian and human
T
T/F. If a single embryo is transferred, yet two embryos have implanted in the uterus, it can be assumed to be a case of monozygotic twins.
T
During the 5th day of human development, you are expected to see 1) ICM, 2) hypoblast,
3) epiblast, 4) primitive streak.
ICM
