Deck 3: Cleavage and Implantation

Question 1

Identical twinning is made possible by what embryonic process?

A)Induction
B)Paternal imprinting
C)X-chromosome inactivation
D)Regulation
E)Maternal imprinting

Answer 1

D

Question 2

The fixation of the left-right asymmetry is initiated by the unequal distribution of molecules at the ____________.

A)Prechordal plate
B)Neural plate
C)Primitive node
D)Notochord
E)None of the above

Answer 2

C

Question 3

When the cleaving embryo implants in the uterine lining,which tissue makes direct contact with the maternal tissues?

A)Inner cell mass
B)Zona pellucida
C)Hypoblast
D)Extraembryonic mesoderm
E)None of the above

Answer 3

E

Question 4

Which tissue from the implanting embryo directly interfaces with the endometrial connective tissue?

A)Inner cell mass
B)Corona radiata
C)Extraembryonic mesoderm
D)Epiblast
E)Syncytiotrophoblast

Question 5

What is the correct cell lineage leading to the formation of the syncytiotrophoblast?

A)Blastomere - inner cell mass - hypoblast - trophoblast - syncytiotrophoblast
B)Inner cell mass - epiblast - cytotrophoblast - syncytiotrophoblast
C)Blastomere - trophoblast - cytotrophoblast - syncytiotrophoblast
D)Blastomere - inner cell mass - epiblast - trophoblast - syncytiotrophoblast
E)Blastomere - epiblast - trophoblast - syncytiotrophoblast

Question 6

A tubal pregnancy can result from:

A)Pelvic inflammatory disease
B)Scarring from a surgical procedure to a uterine tube
C)An anatomical malformation of a uterine tube
D)All of the above
E)None of the above

Question 7

In early development,X inactivation first occurs in what tissue?

A)Inner cell mass
B)Primitive endoderm
C)Notochord
D)Hensen's node
E)Trophectoderm

Question 8

Successful implantation depends on:

A)Dissolution of the zona pellucida
B)Production of syncytiotrophoblast
C)Cell adhesion
D)All of the above
E)None of the above

Question 9

What is the most common condition associated with spontaneously aborted embryos?

A)Maternal imprinting
B)Lithopedion
C)Ectopic pregnancy
D)Chromosomal abnormalities
E)Lack of X-chromosome inactivation

Question 10

Which component(s)of the cleaving embryo give(s)rise to tissues of the embryo itself?

A)Corona radiata
B)Trophoblast
C)Zona pellucida
D)Inner cell mass
E)All of the above

Question 11

The most common site for an ectopic pregnancy is the ________________.

A)Uterus
B)Cervix
C)Abdominal cavity
D)Uterine tube
E)Ovary

Question 12

Which of the following conditions results from inappropriate paternal imprinting?

A)Conjoined twins
B)Parasitic twin
C)Hydatidiform mole
D)Tetraparental mouse
E)Fraternal twins

Question 13

Embryonic stem cells are derived from the _______________.

A)Corona radiata
B)Inner cell mass
C)Cytotrophoblast
D)Syncytiotrophoblast
E)None of the above

Question 14

In the construction of a tetraparental mouse,what property of the cleaving embryo allows the formation of a single mouse from two separate embryos?

A)Induction
B)Bateson's rule
C)Regulation
D)Differentiation
E)Restriction

Question 15

Cells of which of the following are totipotent (can form any part of the embryonic body)?

A)Inner cell mass
B)Cytotrophoblast
C)Amniotic ectoderm
D)Extraembryonic mesoderm
E)Yolk sac endoderm

Question 16

All of the following structures arise from the inner cell mass except:

A)Epiblast
B)Hypoblast
C)Cytotrophoblast
D)Parietal endoderm

Question 17

Which of the following is due to faulty parental imprinting?

A)Ectopic pregnancy
B)Placenta previa
C)Hydatidiform mole
D)Conjoined twins
E)Situs inversus

Question 18

Which of the following is not a function of the zona pellucida?

A)Preventing premature implantation
B)Containing specific sperm receptors
C)Keeping blastomeres of the embryo and its surrounding environment
D)Serving as a filter between the embryo and its surrounding environment
E)Aiding in the penetration of the endometrial epithelium