investigation #3
DESCRIPTION
Investigation #3. Hmm…Make some observations. Go to http ://www.amnh.org/learn/pd/dinos/ gallery.html for a high resolution photo. This fossil was found near Liaoning Province China. Where does this organism “ belong” in the cladogram on the next page? - PowerPoint PPT PresentationTRANSCRIPT
Investigation #3
Hmm…Make some observations.
Go to http://www.amnh.org/learn/pd/dinos/gallery.html for a high resolution photo.
This fossil was found near Liaoning Province China.
Where does this organism “belong” in the cladogram on the next page?
DNA sequence of several genes was obtained. Use this to place the organism.
Fossil Cladogram
heterotroph
vertebrae
fur
Two specialized incisors
RodentsGreat ApesBirdsCrocodilians
Insects
Exposedmouthparts
Crustaceans
Two-parted limbs
Palatal valve featureOpposable thumbs
From page S45 AP Biology Investigative Labs from the College Board.
Download 3 files • http://blogging4biology.edublogs.org/2010/08/28/college-bo
ard-lab-files• Don’t open.
http://blast.ncbi.nlm.nih.gov/Blast.cgi
Click on saved strategies
Many data base choices. This exercise uses nucleotide blast to compare the fossil sequence to known organisms.
Browse for one of the saved files
Don’t change the settings.
Gene 1
Blast
Analysis
Gene entered
Number of results
Red bars compare alignment with the query.
Scroll down.Listed in order of similarity
E value is the likelihood a match occurred by chance. Lower the number the better the match.
Refer to other data bases
This score refers to gaps and substitutions. Higher=more similar alignment
Distance tree of results
Repeat with other genes• Think about your hypothesis in response to the question:
Where does the fossil fit on your cladogram?• Remember: • The higher the score, the closer the alignment.• The lower the e value, the closer the alignment.• Sequences with e values less than 1e-04 (1 x 10-4) can be though
of as related• See page S48 for additional questions and some thoughts on
designing your own investigation.
From the College Board AP Biology Investigative Labs.
Find a gene of interesthttp://www.ncbi.nlm.nih.gov/gene