The annelid worm Glycera dibranchiata has an oxygen binding protein with the same folding pattern as myoglobin. Myoglobins and hemoglobins occur sporadically among invertebrate phyla. It is hard to see a clear, common line of decent from a single ancestor for these species let alone annelids, insects, and vertebrates. No other known protein form has oxygen binding capability. How might these observations best be explained.

Imagine you are a student in alfred hershey and martha chase's lab in the late 1940's. you are given five test tubes with the e. coli bacteria that were infected with t2 bacteriophage that have been labeled with 32p or 35s. unfortunately, you forgot to label the tubes and are now uncertain which were 32p labeled and which were 35s labeled. you place the contents of each tube in a blender and pulse it for a few seconds to shear off the protein coats from the bacterial outer membranes. you then centrifuge the contents to seperate the protein coats and the bacterial cells. you then check for radioactivity and obtain the results shown below. which tubes contained e. coli infected with the phage labeled with 32p? select all tubes that apply.