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* Questions on HOX
  kashmala - 11/08/06 02:53
  Chapter 11: Development of the Limbs
1. An infant exhibits amelia (total absence of a limb). Findings of experimental studies in birds and mice are consistent with the possibility that the limb bud AER failed to express which of the following factors?
A. HOX gene transcription factor
B. Bone morphogenetic substance
C. LIM gene transcription factor
D. WNT gene factor
E. Fibroblast growth factor

2. Recent studies support the likelihood that syndactyly caused by failure of apoptosis between the digital rays may result from disruption of expression of which of the following factors?
A. Bone morphogenetic substance
B. Fibroblast growth factor
C. WNT gene factor
D. Insulin-like growth factor
E. LIM gene transcription factor

3. An infant is born with absence of the ulna and radius and malformations of the carpals and hand. Recent studies show that unique limb segment identities are encoded by HOX genes as follows (scapula - HOX9; humerus - HOX9HOX10; ulna,radius - HOX9HOX10HOX11; proximal carpals - HOX9HOX10HOX11HOX12; distal carpals, metacarpals, phalanges - HOX9HOX10HOX11HOX12HOX13). Therefore, disruption of expression of which of the the following HOX gene families would most likely account for this anomaly?
B. HOX10
C. HOX11
D. HOX12
E. HOX13

4. An infant born with teratogen-induced phocomelia was probably subjected to which of the following teratogenic substances during the indicated sensitive period.
substance sensitive period
retinoic acid
4-8 weeks
2-3 weeks
4-8 weeks
2-3 weeks
4-8 weeks

5. In cases of mirror polydactyly, which of the following factors, produced within the early limb bud, is both expressed by and restricted to the newly formed caudal orthotopic ZPA and the cranial ectopic ZPA?

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* Re:Questions on HOX
  kashmala - 11/08/06 02:58
  answer r

1. E
2. A
3. C
4. E
5. C
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* Re:Questions on HOX
  pashna23 - 11/08/06 03:03
  thanks kash! these are really nice...v helpful  
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* Re:Questions on HOX
  kashmala - 11/08/06 03:07
  u r welcome.thanks for appreciation  
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* Re:Questions on HOX
  cd45 - 11/08/06 03:41
  hehhee thanks kash... was going to take some of the same qssss from the embryo book.. anyways.. now will have to make up.. cya later....  
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* Re:Questions on HOX
  kashmala - 11/08/06 04:50
  u r welcome
c u with Hox tomo
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* Re:Questions on HOX
  mydream - 11/08/06 08:59
  Hey kashmala,
Thank you soooo much for posting such a great topic. I was really needed to do few ques regarding with HOX gene. Can you please tell me what is phocomelia? Once again thak you for ques. Good luck.
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* Re:Questions on HOX
  epcot - 11/08/06 09:17
  thanks kashmala. can u please post the explanation too? what is the source of these Qs?  
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* Re:Questions on HOX
  raptor22 - 11/08/06 10:13
  Thanks kashmala,

That was nice of u,can u post a few more Q's on this topic as i have NO IDEA abt this HOX crap,my exam is on Dec wud be really helpful if u can post some Q's wid explainations....if u have any collection pls mail it to

Thanks & Regards
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* Re:Questions on HOX
  preetipreparing1 - 11/08/06 10:25
  my situation is the same as raptor , can anybody help me too.
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* Re:Questions on HOX
  chicatriste - 11/08/06 10:30
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