ANSC 3040 Final Exam (Animal
Reproduction) Questions With 100%
Correct Answers 2026/2027 Updated.
Conceptus - Answer embryo or fetus + extra embryonic membranes
Ootid - Answer fertilized egg with two pronuclei
Blastomere - Answer embryonic development starts with cellular divisions (cleavage) into cells
called
Morula - Answer will then undergo first round of cell differentiation and formation of ICM and
trophectoderm
ICM - Answer inner cell mass: will from embryo proper
Trophectoderm - Answer will form structure around blastocyst = placenta
Hatching process - Answer 1. blastocyst growth and fluid accumulation 2. production of
enzymes by the trophoblast 3. contraction of the blastocyst
Embryonic genome activation - Answer degradation of maternal RNA and proteins
accumulated in ooplasm during oogenesis; embryo takes 'ownership' of gene expression and
cell biology of blastomeres
when does embryonic genome activation happen? - Answer ruminants: 8-16 cell transition
swine/human: 4-cell
mice: 2-cell
timing of events up to hatching of blastocyst - Answer 2-cell 24 hrs after ovulation (oviduct)
4-cell 36 hrs (oviduct)
8-cell 2-3 d (oviduct, uterus in mare and sow)
morula 4-5 d (uterus)
blastocyst 4-10d (uterus)
hatching 8-9 d (uterus)
13-15 d in bitches, 10-12 in queens
,conceptus development in primates and rodents - Answer attachment and implantation starts
shortly after hatching of blastocyst (hemochorial placentation, highly invasive)
preimplantation development of bovine conceptus - Answer swine/ruminants: elongation of
conceptus occurs after hatching
implantation in ruminants - Answer apposition and adhesion of conceptus cells with
endometrial cells
histotroph - Answer secretes amino acids, proteins, saccharides, growth factors, lipids,
minerals, ions and vitamins
maternal recognition of pregnancy in bovine - Answer secretion of IFN-t by trophectoderm,
blocks upregulation of oxytocin receptors so no pulsatile secretions of PGF2aby the
endometrium so CL is maintained and progesterone secreted
shallow implantation - Answer d20 in cattle and d16 in sheep
bovine crosstalk - Answer ISGs: interferon stimulated gene
conceptus secreting prostaglandins and other molecules changing physiology of endometrial
cells, important for modulation of maternal immune system, required for maternal recognition
of pregnancy and to induce secretion of growth and nutrition factors
elongation of preimplantation conceptus - Answer accumulation of elongation drivers (lipids)
in uterine lumen cause changes in trophectoderm biology and causes elongation (exposure to
progesterone --> lipid droplets accumulation)
elongation causes - Answer cellular reprogramming (from slow to fast differentiation)
rapid proliferation of trophectoderm cells becoming a filamentous conceptus and forming
placenta
cytoskeleton modifications (filamentous)
cellular migration
preimplantation development of porcine conceptus - Answer shallow implantation starts d1;,
at least 2 conceptus per uterine horn required to block luteolysis (no blockage of PGF2a by IFN-
t)
swine can have multiple ovulation
, stages of conceptus development in porcine - Answer spherical --> tubular --> filamentous
porcine conceptus and endometrium crosstalk - Answer modulated by estradiol
maternal recognition of pregnancy in equine - Answer no elongation, conceptus move around
d9-16, and conceptus secretes small amounts of PGF and PGE which induce myometrial
contractions which leads to movement of conceptus --> creates mechanical transduction signal
that minimizes synthesis of PGF2a by endometrium
fixation of equine conceptus - Answer blockage of luteolysis occurs at same time uterine
diameter has decreased and embryo diameter increased; cessation of conceptus mobility d16;
not the same as implantation (occurs d38)
equine conceptus and endometrium crosstalk - Answer mechanotransduction
maternal recognition of pregnancy in bitches and queens - Answer no specific mechanism
since luteal phase duration os observed during pregnancy and in non-pregnant females
implantation bitches and queens occurs when - Answer bitches (d18) queens (d14)
embryonic period - Answer day 0-42 in cattle
formation of zygote after fertilization --> modulation --> blastulation --> gastrulation --> end
with formation of basic structure of organs
fetal period - Answer day 43- term (~278 in cattle)
growth, maturation and remodelling of organ systems, ends with birth of offspring
cell differentiation factors - Answer totipotent blastomere (Cdx2 and Oct4) --> trophoblast or
pluripotent ICM cell (GATA-6 and Nanog) --> hypoblast or pluripotent epiblast
totipotent cells - Answer 2-cell, 4-cell, 8-cell
capable to differentiate into any type of embryonic (body) or extra-embryonic (placenta) cells
multipotent cels - Answer trophectoderm
capable to differentiate into any type of cells within a cell lineage, in this case, placental cells
pluripotent cells - Answer ICM
Reproduction) Questions With 100%
Correct Answers 2026/2027 Updated.
Conceptus - Answer embryo or fetus + extra embryonic membranes
Ootid - Answer fertilized egg with two pronuclei
Blastomere - Answer embryonic development starts with cellular divisions (cleavage) into cells
called
Morula - Answer will then undergo first round of cell differentiation and formation of ICM and
trophectoderm
ICM - Answer inner cell mass: will from embryo proper
Trophectoderm - Answer will form structure around blastocyst = placenta
Hatching process - Answer 1. blastocyst growth and fluid accumulation 2. production of
enzymes by the trophoblast 3. contraction of the blastocyst
Embryonic genome activation - Answer degradation of maternal RNA and proteins
accumulated in ooplasm during oogenesis; embryo takes 'ownership' of gene expression and
cell biology of blastomeres
when does embryonic genome activation happen? - Answer ruminants: 8-16 cell transition
swine/human: 4-cell
mice: 2-cell
timing of events up to hatching of blastocyst - Answer 2-cell 24 hrs after ovulation (oviduct)
4-cell 36 hrs (oviduct)
8-cell 2-3 d (oviduct, uterus in mare and sow)
morula 4-5 d (uterus)
blastocyst 4-10d (uterus)
hatching 8-9 d (uterus)
13-15 d in bitches, 10-12 in queens
,conceptus development in primates and rodents - Answer attachment and implantation starts
shortly after hatching of blastocyst (hemochorial placentation, highly invasive)
preimplantation development of bovine conceptus - Answer swine/ruminants: elongation of
conceptus occurs after hatching
implantation in ruminants - Answer apposition and adhesion of conceptus cells with
endometrial cells
histotroph - Answer secretes amino acids, proteins, saccharides, growth factors, lipids,
minerals, ions and vitamins
maternal recognition of pregnancy in bovine - Answer secretion of IFN-t by trophectoderm,
blocks upregulation of oxytocin receptors so no pulsatile secretions of PGF2aby the
endometrium so CL is maintained and progesterone secreted
shallow implantation - Answer d20 in cattle and d16 in sheep
bovine crosstalk - Answer ISGs: interferon stimulated gene
conceptus secreting prostaglandins and other molecules changing physiology of endometrial
cells, important for modulation of maternal immune system, required for maternal recognition
of pregnancy and to induce secretion of growth and nutrition factors
elongation of preimplantation conceptus - Answer accumulation of elongation drivers (lipids)
in uterine lumen cause changes in trophectoderm biology and causes elongation (exposure to
progesterone --> lipid droplets accumulation)
elongation causes - Answer cellular reprogramming (from slow to fast differentiation)
rapid proliferation of trophectoderm cells becoming a filamentous conceptus and forming
placenta
cytoskeleton modifications (filamentous)
cellular migration
preimplantation development of porcine conceptus - Answer shallow implantation starts d1;,
at least 2 conceptus per uterine horn required to block luteolysis (no blockage of PGF2a by IFN-
t)
swine can have multiple ovulation
, stages of conceptus development in porcine - Answer spherical --> tubular --> filamentous
porcine conceptus and endometrium crosstalk - Answer modulated by estradiol
maternal recognition of pregnancy in equine - Answer no elongation, conceptus move around
d9-16, and conceptus secretes small amounts of PGF and PGE which induce myometrial
contractions which leads to movement of conceptus --> creates mechanical transduction signal
that minimizes synthesis of PGF2a by endometrium
fixation of equine conceptus - Answer blockage of luteolysis occurs at same time uterine
diameter has decreased and embryo diameter increased; cessation of conceptus mobility d16;
not the same as implantation (occurs d38)
equine conceptus and endometrium crosstalk - Answer mechanotransduction
maternal recognition of pregnancy in bitches and queens - Answer no specific mechanism
since luteal phase duration os observed during pregnancy and in non-pregnant females
implantation bitches and queens occurs when - Answer bitches (d18) queens (d14)
embryonic period - Answer day 0-42 in cattle
formation of zygote after fertilization --> modulation --> blastulation --> gastrulation --> end
with formation of basic structure of organs
fetal period - Answer day 43- term (~278 in cattle)
growth, maturation and remodelling of organ systems, ends with birth of offspring
cell differentiation factors - Answer totipotent blastomere (Cdx2 and Oct4) --> trophoblast or
pluripotent ICM cell (GATA-6 and Nanog) --> hypoblast or pluripotent epiblast
totipotent cells - Answer 2-cell, 4-cell, 8-cell
capable to differentiate into any type of embryonic (body) or extra-embryonic (placenta) cells
multipotent cels - Answer trophectoderm
capable to differentiate into any type of cells within a cell lineage, in this case, placental cells
pluripotent cells - Answer ICM
