Early Embryogenesis 1 (Ch.13) Flashcards
What does syngamy refer to?
When does this occur?
The fusion of male and female DNA
When the embryo goes from a ootid to a zygote and the DNA is completely replicated
What does not grow during the early mitosis stage of embryo’s?
Why?
The cytoplasm
It is energy expensive
The crucial transition in the early stages of embryonic development is when the embryo goes from ___ to ___
Morula
Early blastocyst
What is a totipotent cell?
A embryonic cell that has yet to differentiate at all and can become any cell it wants to
(T/F) All cells in the early embryo start as totipotent
True!
What is a pluripotent cell?
A embryonic cell that has differentiated into its general area (placental, cardiovascular)
(T/F) Pluripotent cells can differentiate into any cell they want to
False!
Only totipotent cells can do this
What is a degenerate embryo?
An embryo in which all the cells have died
An embryo will remain in the oviduct until around day (#)
4
(T/F) An embryo recovered in the oviduct can be transferred into a recipients uterus
False!
Must be transferred to the recipients oviduct
At which embryonic stage does it become hard to count the total number of cells?
Morula
What embryonic stage is characterized by a fluid filled cavity?
Blastula
A perfect embryo is given a Grade (#)
1
Describe a Grade 2 embryo
An embryo that contains some dead cells that do no divide
(#)% of fertile human embryos will die before they know pregnancy has occurred
50%
The development of a ___ is when the female will know she is pregnant
Placenta
(T/F) The formation of gap junctions and tight junctions signifies the end of totipotency
True!
A sudopregnancy will last for (#) days before the female knows that no viable offspring is present
40 days
(T/F) Only placental cell types are required for a viable embryo to develop
False!
Need placental AND fetal cells
The morula stage of embryonic development can be found in the (oviduct/uterus)
Uterus
All early embryonic cell divisions occurs within the ___
Zona pellucida
Describe implantation
What is the difference between livestock and humans?
When an embryo makes contact with the uterus
Livestock will stop at stage 4 (adhesion)
Human embryos will penetrate the endometrium
(T/F) Livestock embryos will penetrate the endometrium of the uterus
False!
This does not happen in livestock, it happens in humans
The formation of what two structures signifies the end of tonipotency?
Gap junctions and tight junctions
