ANSC 333 EXAMINATION TEST PAPER 2026
FULL QUESTIONS AND SOLUTIONS
◉ zygote
Answer: single cell embryo
◉ blastomere
Answer: two-celled embryo
◉ same size as zygote, represents 1/2 of the single-celled zygote
Answer: blastomere characteristics
◉ zygote undergoes series of mitotic divisions, only replicating the
DNA- no production of cytoplasm
Answer: What does the zygote undergo?
◉ morula
Answer: embryos with >32 cells
◉ oviduct
,Answer: Where does all early embryonic development occur?
◉ compaction
Answer: Once the morula reaches 64 cells, what does it initiate?
◉ compaction
Answer: process through which cells in the morula begin to stick
together
◉ totipotent
Answer: if a cell can become any cell that is needed, blastomeres
◉ cells on the inside of the morula form gap junctions- become the
fetus
cells lining the zona pellucida form tight junctions- becomes the
placenta
Answer: When compaction occurs, cells are no longer totipotent.
How do they differentiate?
◉ pluripotent
Answer: Cell has made at least one decision, but is not yet fully
differentiated, occurs during and after compaction
, ◉ uterus
Answer: where does compaction occur?
◉ blastocyst
Answer: blastocoele has a defined fluid filled cavity inside it
◉ trophoblast cells
Answer: Cells with the tight junctions found in the outer cell
◉ inner cell mass
Answer: Cells with gap junctions found among the inner cell
◉ Chorion
Answer: What will the trophoblast cells form?
◉ embryo
Answer: What will the inner cell mass form?
◉ fetal side of the placenta
Answer: What is the chorion?
◉ pump water into blastocoele to weaken the zona pellucida
FULL QUESTIONS AND SOLUTIONS
◉ zygote
Answer: single cell embryo
◉ blastomere
Answer: two-celled embryo
◉ same size as zygote, represents 1/2 of the single-celled zygote
Answer: blastomere characteristics
◉ zygote undergoes series of mitotic divisions, only replicating the
DNA- no production of cytoplasm
Answer: What does the zygote undergo?
◉ morula
Answer: embryos with >32 cells
◉ oviduct
,Answer: Where does all early embryonic development occur?
◉ compaction
Answer: Once the morula reaches 64 cells, what does it initiate?
◉ compaction
Answer: process through which cells in the morula begin to stick
together
◉ totipotent
Answer: if a cell can become any cell that is needed, blastomeres
◉ cells on the inside of the morula form gap junctions- become the
fetus
cells lining the zona pellucida form tight junctions- becomes the
placenta
Answer: When compaction occurs, cells are no longer totipotent.
How do they differentiate?
◉ pluripotent
Answer: Cell has made at least one decision, but is not yet fully
differentiated, occurs during and after compaction
, ◉ uterus
Answer: where does compaction occur?
◉ blastocyst
Answer: blastocoele has a defined fluid filled cavity inside it
◉ trophoblast cells
Answer: Cells with the tight junctions found in the outer cell
◉ inner cell mass
Answer: Cells with gap junctions found among the inner cell
◉ Chorion
Answer: What will the trophoblast cells form?
◉ embryo
Answer: What will the inner cell mass form?
◉ fetal side of the placenta
Answer: What is the chorion?
◉ pump water into blastocoele to weaken the zona pellucida
