dev bio mammal quiz 3

what is cleavage?

early cell divisions after fertilization

gastrulation is best defined as:

formation of the three germ layers

what is not an axis established during early development?

proximal-distal

mammals are classified as:

deuterostomes

in deuterostomes, the blastopore becomes the:

anus

matching: gas exchange and nutrient transfer

chorion

matching: waste storage

allantois

matching: “water sac” surrounding embryo

amnion

matching: nutrient uptake and circulation development

yolk sac

matching: exchange organ between mother and embryo

placenta

true or false: cleavage increases cytoplasmic volume

false

true or false: blastomeres are cells formed during cleavage

true

true or false: mammalian cleavage is synchronous

false

true or false: fertilization occurs in the uterus

false (ampulla)

true or false: zygotic genome activation occurs later in mammals than in most organisms

true

true or false: compaction occurs at the 2-cell stage

false (8-cell)

where does fertilization typically occur in mammals?

the ampulla of the oviduct

what triggers calcium release in the oocyte after fertilization?

PLC-Zeta from sperm triggers Ca2+ release

what type of cleavage occurs in mammals?

rotational holoblastic cleavage

what happens during rotational cleavage?

one blastomere divides meridionally and the other equatorially

what is meridional division?

vertical division

what is equatorial division?

horizontal division

what is MPF made of?

cyclin B + cdc2

what is compaction?

cells become tightly packed and polarized

what molecule is important for compaction?

E-cadherin

what does nanog specify?

epiblast

what does gata6 specify?

primitive endoderm

what is cavitation?

formation of fluid-filled cavity

what is the chorion?

embryonic part of placenta

what is the decidua?

maternal uterine tissue forming placenta

what is the primary goal of cleavage?

rapid increase in cell number

what is the establishment of spatial orientation (guides proper tissue and organ placement)

axis determination

which developmental process do all animals share?

gastrulation

what comes from the mouth of the blastopore?

protostomes

what comes from the anus of the blastopore?

deuterostomes

in protostomes, the blastopore becomes the:

mouth

what are the two cell populations formed during the first fate decision?

ICM and TE

what does the TE eventually contribute to?

the placenta

what structure does the primitive endoderm (hypoblast) contribute to?

yolk sac

which gene is associated with epiblast identity?

nanog

which gene is associated with primitive endoderm identity?

gata6

which type of movement involves sheets of cells folding inward?

invagination

what do cells lose typically during ingression?

E-cadherins

where does gastrulation begin in mammals?

at the posterior end of the embryo

what structure forms at the site where cells migrate inward?

primitive streak

which signaling molecules are important for anterior-posterior patterning?

retinoid acid (RA) and Fgfs

what region of the embryo has low BMP and Wnt activity?

the anterior region

what happens if Hox10 genes are knocked out?

no lumbar vertebrae

what is the movement of a sheet of cells folding inwards as a group?

invagination

what is it when individual cells detach and migrate inward after EMT?

ingression