Embryology — Flashcards

Flashcard 31: Where is the FGF gene expressed?

Answer: apical ectodermal ridge (distal end of limb bud)

Flashcard 32: Sonic hedgehog gene is involved with patterning of which body axis?

Answer: anterior-posterior

Flashcard 33: Wnt-7 gene is involved with patterning of which body axis?

Answer: dorsal-ventral

Flashcard 34: What processes are directed by Hox genes?

Answer: segmentation of embryo in cranial-caudal axis

Flashcard 35: What kinds of defects are caused by Hox mutations?

Answer: appendages in wrong places

Flashcard 36: The primitive streak, notochord, mesoderm, and neural plate form during week _____ of embryogenesis.

Answer: 3

Flashcard 37: The heart begins to beat during _____ of embryogenesis.

Answer: week 4

Flashcard 38: The limb buds begin to form during _____ of embryogenesis.

Answer: week 4

Extra: 4 weeks =  4 limbs

Flashcard 39: The three germ layers are _____

Answer: endoderm, mesoderm, and ectoderm.

Flashcard 40: The three divisions of the ectoderm are _____.

Answer: surface ectoderm, neuroectoderm, and neural crest