Deck 10: Organogenesis

Question 1

The apical ectodermal ridge runs in which direction in the developing limb bud?

A) Antero-posterior
B) Dorso-ventral
C) Proximo-distal
D) Left-right

Answer 1

B

Question 2

What is the correct flow of interactions that determines proper positioning and outgrowth of the forelimb?

A) Lateral plate - Hox - Tbx5 - FGF-10 - apical ectodermal ridge
B) Lateral plate - Tbx4 - Hox - FGF-10 - apical ectodermal ridge
C) Lateral plate - Hox - Tbx4 - FGF-10 - apical ectodermal ridge-
D) Lateral plate - Tbx5 - Hox - FGF-10 - apical ectodermal ridge

Answer 2

A

Question 3

Which of the following refers to a chemical or infection that interferes with embryonic development, leading to defects in the animal?

A) Teratogen
B) Mutagen
C) Morphogen
D) Carcinogen

Answer 3

A

Question 4

Which of the following intercellular signaling pathways directly controls the sequence of limb digits across the antero-posterior axis?

A) FGF
B) Shh
C) Wnt
D) BMP

Question 5

Which of the following intercellular signaling pathways directly controls the direction of knee and knuckle bending?

A) FGF
B) Shh
C) Wnt
D) Notch

Question 6

Which mechanism underlies the formation of separate digits?

A) FGF induces apoptosis of interdigital cells
B) Lack of FGF induces necrosis of interdigital cells
C) BMP induces apoptosis of interdigital cells
D) Lack of BMP induces necrosis of interdigital cells

Question 7

Which axis in the Drosophila wing is inherited through engrailed expression from the embryonic parasegment?

A) Antero-posterior
B) Dorso-ventral
C) Proximo-distal
D) Left-right

Question 8

Which of the following is synthesized along the antero-posterior wing boundary to act as a morphogen to cells in both compartments?

A) Decapentaplegic (Dpp)
B) Spalt (Sal)
C) Brinker (Brk)
D) Optomotorblind (Omb)

Question 9

Which of the following tissues signals to the overlying ectoderm in a vertebrate embryo to induce the lens placode?

A) Surface ectoderm
B) Neural retina
C) Cornea
D) Optic vesicle

Question 10

Which of the following is not true of the pax6 gene?

A) Loss of Pax6 function in humans leads to aniridia
B) Ectopic pax6 expression induces eye development in non-eye imaginal discs
C) Pax6 function is evolutionarily conserved
D) It encodes a intercellular signaling receptor