Deck 5: Laying Down and Completing the Vertebrate Body Plan: Chick and Mouse

Question 1

What determines the orientation of the antero-posterior axis in the epiblast of a chick embryo?

A) A random process
B) Interaction with the surrounding albumin
C) Gravity effects on the embryo
D) It is oriented away from the site of sperm entry

Answer 1

C

Question 2

Which of the options given is the Nieuwkoop center analog in the chick embryo?

A) Anterior marginal zone
B) Posterior marginal zone
C) Area pellucida
D) Area opaca

Answer 2

B

Question 3

Which of the following is not true of the trophectoderm?

A) Cells on the morula's periphery tend to become trophectoderm
B) Formation of the trophectoderm is the first differentiation event in mammalian embryonic development
C) The transcription factor Oct4 promotes trophectoderm formation
D) Mouse chimeras have been used to study trophectoderm specification

Answer 3

C

Question 4

What is the result of Gata6 expression within the inner cell mass?

A) Cells differentiate into a layer of primitive endoderm
B) Cells differentiate into trophoblasts
C) Cells differentiate into epiblast
D) Cells revert back to a more pluripotent state

Question 5

What is another way of referring to the paraxial mesoderm?

A) Intermediate mesoderm
B) Somitic mesoderm
C) Lateral plate mesoderm
D) Notochord

Question 6

What is the signaling protein responsible for initiating neural tissue induction in the chick embryo?

A) FGF
B) BMP
C) Chordin
D) Cerberus

Question 7

Which of the following is not true of somites?

A) Somites give rise to bone, cartilage, and muscle of the body axis
B) Two somites form simultaneously
C) Somites form rhythmically from posterior to anterior
D) Somites are formed from mesoderm adjacent to the neural tube

Question 8

What does the "clock and wavefront" model propose?

A) Cells must undergo a specific number of oscillations of gene activity in order to form a somite
B) Cells must be passed by the wavefront to commit to forming a somite
C) Cells must not have yet been passed by the wavefront to commit to forming a somite
D) Genes that position a wavefront have clock-like gene expression

Question 9

Which of the following genes determines the identity of somites in mouse and chick embryos and can be disrupted in order to induce transformations or antero-posterior shifts in vertebral fate?

A) Hox
B) BMP
C) Fgf
D) Notch

Question 10

The sclerotome region of a somite gives rise to vertebrae and ribs. From which tissues does the sclerotome receive signals to direct these fates?

A) Lateral plate mesoderm
B) Notochord and floor plate
C) Roof plate and overlying ectoderm
D) Endoderm