Rider bridge 2001 2002
Download
1 / 10

Rider BRIDGE 2001-2002 - PowerPoint PPT Presentation


  • 48 Views
  • Uploaded on

Rider BRIDGE 2001-2002. BIO115: Introductory Biology J. Drawbridge. What the students see. What I see (Fridays). Pilot Experiment SP/02 Developmental Biology. Craig Nelson - 5 point, take-home students complete in blue ink in class revision in groups (red ink) class discussion of answers.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Rider BRIDGE 2001-2002' - ifeoma-young


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Rider bridge 2001 2002
Rider BRIDGE 2001-2002

BIO115: Introductory Biology

J. Drawbridge




Pilot experiment sp 02 developmental biology
Pilot Experiment SP/02Developmental Biology

  • Craig Nelson - 5 point, take-home

    • students complete in blue ink

    • in class revision in groups (red ink)

    • class discussion of answers


Example
Example

  • On 5 point sheet

    • Explain how Hox genes specify the location of limb buds along the anterior-posterior axis.

    • If Hox genes specify limb bud location, why can you get extra limbs if you implant FGF beads into the flank?

  • On Exam

    • Would a limb form if you implanted an FGF bead in the flank of a snake embryo? Why, why not? Would it be a forelimb or hindlimb? Why?


Raccoon

Snake


Sample Answers:

  • If Hox genes specify where limb buds form, why can you get extra limbs if you implant FGF bead into the flank.

  • " FGF is a paracrine factor secreted by the lateral plate mesoderm and induces the AER. Hox genes code for FGF proteins, so the FGF would induce the AER as if the Hox gene was there and had turned on FGF. Hox gene  FGF  AER Limb. FGF is downstream of Hox genes"

  • "because the FGF paracrine factor is capable of limb forming interactions between the ectoderm and mesoderm. If the beads are placed ectopically beneath the flank ectoderm, extra limbs emerge. FGF bead bypasses HOX genes"


Sample Answers:

  • Explain how Hox genes specify the location of limb buds along the anterior-posterior axis.

  • " Hox genes along the anterior posterior axis specifies the limb buds. Hox genes on the 3' end are for the anterior.....Also, there is a gradient of retinoic acid that may activate certain Hox genes and specify them to be included in the limb field. position of the limbs defined by location of Hox genes"

  • "arms between Hox 5 & 6; legs between Hox 9 & 10. position of limbs determined where Hox genes are located"


Sample Answers (exam):

  • Would a limb form if you implanted an FGF bead in the flank of a snake embryo? Why, why not? Would it be a forelimb or hindlimb? why?

  • " Yes, a limb bud would form...downstream of Hox genes is FGF. This doesn't happen in a normal snake because it doesn't express the proper Hox genes in the proper location. It would form a forelimb because snakes have mostly thoracic vertebrae and the forelimb is made at the junction of the cervical and thoracic vertebrae. Hindlimbs are made at the lumbar-sacral junction which snakes don't have, so they wouldn't make hindlimbs"

  • "...FGF bead would form a limb. Since a snake is nearly all thoracic vertebrae, and FGF bead would create small forelimbs by expressing the Tbx5 transcription factor"


Summary
Summary

  • 5 point sheets must count

  • misconceptions MUST be addressed

  • thought questions

  • follow up questions on exam

  • BIO300 Exam average FA/99 - 60.5

  • BIO300 Exam average SP/02 - 73.4


ad