Bio 325 Exam 4 Questions With Correct
Answers
How |does |the |limb |know |where |to |form? |- |CORRECT |ANSWER✔✔-through |hox |genes
Hypaxial |Myotome |- |CORRECT |ANSWER✔✔-makes |muscle
What |is |the |name |of |the |precursors |for |muscles? |- |CORRECT |ANSWER✔✔-myoblasts
what |is |the |role |of |the |apical |Ectodermal |ridge? |- |CORRECT |ANSWER✔✔-allow |limb |to |grow |
outward
Where |is |fgf10 |expressed? |- |CORRECT |ANSWER✔✔-in |the |future |forelimbs |and |hindlims
what |is |the |order |of |the |things |that |need |to |be |expressed |to |get |a |limb? |- |CORRECT |
ANSWER✔✔-hox |proteins--> |RA--> |Tbx |transcription |factors--> |fgf10--> |fgf8
Where |is |are |hox |genes |expressed? |- |CORRECT |ANSWER✔✔-in |the |LPM
What |is |the |holt-oram |syndrome? |- |CORRECT |ANSWER✔✔--a |mutation |in |tbx5 |where |
forearms |aren't |developed.
-it |can |also |affect |the |heart
-autosomal |disease
autosome |- |CORRECT |ANSWER✔✔-not |a |chromosome
, what |is |the |name |of |the |mesoderm |underneath |the |AER? |- |CORRECT |ANSWER✔✔-progress |
zone
What |happens |if |you |scrape |off |the |AER? |- |CORRECT |ANSWER✔✔-the |limb |stops |growing
what |happens |if |you |add |an |extra |AER |to |the |limb |bed? |- |CORRECT |ANSWER✔✔-the |limb |will |
have |duplicated |structures; |you |get |duplicated |digits.
describe |the |positive |feedback |starting |from |how |genes |to |the |AER |- |CORRECT |ANSWER✔✔-
Lateral |plate |mesoderm |is |expressing |Hox |genes, |Hox |genes |is |activates |synthesis |of |RA |and |
RA |causes |induction |of |transcription |factors: |Tbx |4 |& |5. |This |then |stimulates |paracrine |factor, |
fgf10 |expression |in |the |LPM. |That |fgf10 |expression |activates |Wnt |expression |in |the |surface |
ectoderm |and |the |Wnt |helps |activate |fgf8 |in |surface |ectoderm. |Once |Fgf8 |is |made, |the |surface
|ectoderm |elongates |to |become |the |Apical |Ectodermal |Ridge |(AER) |. |The |AER |is |a |source |for |
FGFs |for |limb |outgrowth |and |patterning. |It |tells |the |mesenchyme |cells |directly |beneath |it |to |
continue |to |make |Fgf10. |That |will |create |a |positive |feedback |feedback |to |the |mesoderm |and |
activate |proliferation |so |that |the |cells |underneath |the |ectoderm |can |proliferate. |The |more |
cells |produced, |the |more |the |limb |bud |will |push |out.
what |is |the |name |of |distal |mesenchyme |right |underneath |the |AER? |- |CORRECT |ANSWER✔✔-
progress |zone
____ |is |thought |to |be |a |proximilizing |agent |- |CORRECT |ANSWER✔✔-Retanoic |acid
Importance |of |wnt |5a |- |CORRECT |ANSWER✔✔-it |controls |the |mesenchyme |cells |using |planar |
cell |polarity |so |that |they |move |towards |the |AER. |Cells |that |move |closer |to |the |AER |become |
distal |and |cells |farther |away |become |proximal. |So
what |happens |when |you |have |no |treatment |(no |wnt3a,fgf |& |RA) |aka |serum |- |CORRECT |
ANSWER✔✔-you |have |some |expression |of |meis1
Answers
How |does |the |limb |know |where |to |form? |- |CORRECT |ANSWER✔✔-through |hox |genes
Hypaxial |Myotome |- |CORRECT |ANSWER✔✔-makes |muscle
What |is |the |name |of |the |precursors |for |muscles? |- |CORRECT |ANSWER✔✔-myoblasts
what |is |the |role |of |the |apical |Ectodermal |ridge? |- |CORRECT |ANSWER✔✔-allow |limb |to |grow |
outward
Where |is |fgf10 |expressed? |- |CORRECT |ANSWER✔✔-in |the |future |forelimbs |and |hindlims
what |is |the |order |of |the |things |that |need |to |be |expressed |to |get |a |limb? |- |CORRECT |
ANSWER✔✔-hox |proteins--> |RA--> |Tbx |transcription |factors--> |fgf10--> |fgf8
Where |is |are |hox |genes |expressed? |- |CORRECT |ANSWER✔✔-in |the |LPM
What |is |the |holt-oram |syndrome? |- |CORRECT |ANSWER✔✔--a |mutation |in |tbx5 |where |
forearms |aren't |developed.
-it |can |also |affect |the |heart
-autosomal |disease
autosome |- |CORRECT |ANSWER✔✔-not |a |chromosome
, what |is |the |name |of |the |mesoderm |underneath |the |AER? |- |CORRECT |ANSWER✔✔-progress |
zone
What |happens |if |you |scrape |off |the |AER? |- |CORRECT |ANSWER✔✔-the |limb |stops |growing
what |happens |if |you |add |an |extra |AER |to |the |limb |bed? |- |CORRECT |ANSWER✔✔-the |limb |will |
have |duplicated |structures; |you |get |duplicated |digits.
describe |the |positive |feedback |starting |from |how |genes |to |the |AER |- |CORRECT |ANSWER✔✔-
Lateral |plate |mesoderm |is |expressing |Hox |genes, |Hox |genes |is |activates |synthesis |of |RA |and |
RA |causes |induction |of |transcription |factors: |Tbx |4 |& |5. |This |then |stimulates |paracrine |factor, |
fgf10 |expression |in |the |LPM. |That |fgf10 |expression |activates |Wnt |expression |in |the |surface |
ectoderm |and |the |Wnt |helps |activate |fgf8 |in |surface |ectoderm. |Once |Fgf8 |is |made, |the |surface
|ectoderm |elongates |to |become |the |Apical |Ectodermal |Ridge |(AER) |. |The |AER |is |a |source |for |
FGFs |for |limb |outgrowth |and |patterning. |It |tells |the |mesenchyme |cells |directly |beneath |it |to |
continue |to |make |Fgf10. |That |will |create |a |positive |feedback |feedback |to |the |mesoderm |and |
activate |proliferation |so |that |the |cells |underneath |the |ectoderm |can |proliferate. |The |more |
cells |produced, |the |more |the |limb |bud |will |push |out.
what |is |the |name |of |distal |mesenchyme |right |underneath |the |AER? |- |CORRECT |ANSWER✔✔-
progress |zone
____ |is |thought |to |be |a |proximilizing |agent |- |CORRECT |ANSWER✔✔-Retanoic |acid
Importance |of |wnt |5a |- |CORRECT |ANSWER✔✔-it |controls |the |mesenchyme |cells |using |planar |
cell |polarity |so |that |they |move |towards |the |AER. |Cells |that |move |closer |to |the |AER |become |
distal |and |cells |farther |away |become |proximal. |So
what |happens |when |you |have |no |treatment |(no |wnt3a,fgf |& |RA) |aka |serum |- |CORRECT |
ANSWER✔✔-you |have |some |expression |of |meis1
