Cuyamaca College Phylogenetic Tree Bacterium 16srRNA Sequences Lab Discussion

answer the questions below about the lab provided

Question 16 pts

1. Upload your phylogenetic tree here.

Print out the alignment of the 16srRNA sequences of your assigned bacterium and the 4 most closely related bacteria. How many nucleotide changes distinguish each of these organisms? What are the major biochemical differences between these organisms?

3. Do the relationships of the taxa in the phylogenetic tree agree with those predicted from ta tree based strictly on phenotypes? Describe two ways in which the relationships are likely to be similar and two ways in which they are likely to differ.

4. Even with the limited number of sequences involved, the unrooted phylogenetic tree allows the recognition of three large groups of organisms. these groups are called Domains. On your phylogenetic tree, circle each Domain and give each its correct name.

5. Predict where each of the following taxa would be located in your unrooted tree: homo sapiens(#337376) and Candida albicans (you will have to look up this GenBank Accession number yourself). Check your predictions by adding the indicated sequences to your list and redrawing the phylogenetic tree. Turn in the revised tree with your answers. Be sure to use 18S ribosomal RNA when you search these sequences.

6. It is possible to identify uncultured microbes in environmental samples ny using PCR primers that amplify the 16s rRNA, sequencings the amplified DNA fragment, and using the sequence to place the organism on the phylogenic tree. What does the placement of the 16s sequence AJ606250 tell you about the organism?

7. All but one of the prokaryotes with peptidoglycan in their cell walls are Archae. What group is the exception and why?