ZOO 3603C - Exam 3 Practice Questions With Accurate Answers

ZOO 3603C - Exam 3 Practice Questions
With Accurate Answers
Limb Dev I: Name the parts of the limb - Correct Answer Stylopod: humerus, femur
Zeugopod: ulna + radius, tibia + fibula
Autopod: wrist + fingers, ankle + toes

Limb Dev I: what tissue does the limb bud emerge from? - Correct Answer the flank
lateral plate mesoderm
(upper LPM)

Limb Dev I: what does the somite position of the limb bud determine? - Correct Answer
neck length

Limb Dev I: where does the limb bud appear in every animal? - Correct Answer at the
same Hox position
border of c5 and c6

Limb Dev I: what is the limb bud composed of? - Correct Answer epithelium covering
two types of mesenchymal cells

Limb Dev I: what are the two types of mesenchymal cells that the limb bud is composed
of? - Correct Answer Lateral plate mesenchyme
somitic cells

Limb Dev I: what do the somitic cells make in the limb bud? - Correct Answer
myoblasts of the limbs, muscle fibers
NOT connective tissues

Limb Dev I: what happens in the limb bud/adult limb if you remove somite? - Correct
Answer no muscle or muscle fibers

Limb Dev I: what is the gene that shows evidence for somitic migration into the limb
bud? - Correct Answer Pax 3

Limb Dev I: what is the receptor for Pax 3? - Correct Answer c-met

Limb Dev I: what is the ligand for c-met? - Correct Answer HGF
expressed in distal limb bud

Limb Dev I: what are splotch mice? - Correct Answer they have no limb muscles,
because no migration of somitic cells into the limb because no Pax3

Limb Dev I: what is the role of Lbx in the limb bud? - Correct Answer involved in
production of extensors and flexors. Without Lbx, extensors and flexors are reduced

, Limb Dev I: what sculpts the limb? - Correct Answer cell death

Limb Dev I: what induces cell death that separates digits in the developing limb bud? -
Correct Answer BMP4

Limb Dev I: what is the progress zone responsible for? - Correct Answer outgrowth
differentiated elements "drop out" from the PZ, first the humerus, then radius/ulna,
carpals, and digits in a proximodistal sequence

Limb Dev I: what type of information does the PZ give to the limb bud? - Correct Answer
Level-specific information
There is no communication between PZ and stump of limb. If you attach it to a different
limb bud, it will continue to develop as if it were attached to the old one

Limb Dev I: what appears that the tip of the limb bud? - Correct Answer the apical
ectodermal ridge
AER

Limb Dev I: what is the AER responsible for? - Correct Answer outgrowth

Limb Dev I: what happens if you move the AER from the limb bud - Correct Answer it
freezes development at that time

Limb Dev I: what type of information does the AER give to the limb? - Correct Answer
NOT level-specific
NOT wing or leg specific
NOT species-specific

ONLY responsible for saying grow

Limb Dev I: what organizes that anteroposterior (AP) axis of the limb bud? - Correct
Answer the zone of polarizing activity
ZPA
Contains molecules specifying for posterior limb bud

Limb Dev II: what happens if you take away RA? - Correct Answer no limbs

Limb Dev II: what happens when you knock out Raldh2 in the mouse embryo? - Correct
Answer forelimb gone, hind limb okay

Limb Dev II: In what situation is there experimental evidence of limb initiation by RA? -
Correct Answer limb regeneration

Limb Dev II: what molecules do initiate new limbs? - Correct Answer FGF4
FGF10
Wnt