Mammals

Question 1

Are mammals considered amniotes?

Answer 1

Yes

Question 2

What are some of the corollary pieces that placental mammals and birds have in common?

Answer 2

The amniotic cavity, Amnion, Allantois, Chorion, Yolk Sac

Question 3

What stage is the embryo at when it enters the uterus?

Answer 3

The blastocyst stage.

Question 4

What important event changes embryo size at the 8 cell stage?

Answer 4

Compaction

Question 5

What two features does compaction require?

Answer 5

Adherens and tight junctions, E cadherin,

Question 6

What are different cell types at the blastocyst stage?

Answer 6

Inner cell mass cells, blastocoel, trophoblasts.

Question 7

Define # of Chorions and Amnions in the early, later, and very late stages of twins.

Answer 7

Early: 2 amnions, and chorions
Later: 2 amnions, and one chorion
Very late: one chorion, and one amnion.

Question 8

What can be concluded about the pluripotency of the ICM from twin experiments?

Answer 8

Pluripotency is maintained until immediately prior to gastrulation.

Question 9

What factor is required for pluripotency and how do we see this?

Answer 9

Oct 4 (Yamanaka factor) is required and is only in ICM, but not trophoblast cells.