Body axis formation

Question 1

What is the primary signaling pathway involved in establishing the anterior-posterior axis during embryonic development?
a) Notch signaling
b) Wnt signaling
c) Hedgehog signaling
d) BMP signaling

Answer 1

Answer: b) Wnt signaling

Question 2

Which cellular structure plays a crucial role in patterning the dorsal-ventral axis in early vertebrate embryos?

Answer 2

a) Notochord
b) Neural tube
c) Blastopore
d) Spemann’s organizer

Answer: d) Spemann’s organizer

Question 3

Which of the following is a key regulator of left-right axis determination in vertebrates?
a) Sonic hedgehog
b) Nodal
c) FGF signaling
d) Delta-Notch signaling

Answer 3

Nodal

Question 4

What is the name of the structure in the developing embryo that establishes the proximal-distal axis by secreting signaling molecules like FGFs?
a) Apical ectodermal ridge (AER)
b) Zone of polarizing activity (ZPA)
c) Organizer
d) Blastocoel

Answer 4

a) Apical ectodermal ridge (AER)

Question 5

In limb development, which signaling pathway is responsible for specifying the identity of different limb segments along the proximal-distal axis?

Answer 5

Answer: c) Shh signaling

Question 6

Important in establishing the left-sideness of the embryo

Answer 6

FGF8

Question 7

Specification of forelimbs is regulated by transcription factor

Answer 7

TBX5

Question 8

Specification of Hind limbs is regulated by transcription factor

Answer 8

TBX4

Question 9

After AER is extablished it expresses ___ and ___ which maintains the undifferentiated zome

Answer 9

FGF 4 and FGF 8

Question 10

Differentiation of zeugopod (middle segment of the limb)

Answer 10

HOX11

Question 11

Differentiation of autopod (distal segment of the limb)

Answer 11

HOX13

Question 12

what plays a role in ensuring that digits appear in the proper order of the digits

Answer 12

ZPA and SHH