Imagine you are a student in Alfred Hershey and Martha Chase

Imagine you are a student in Alfred Hershey and Martha Chase\'s lab in the late 1940s. You are given five test tubes with the E coli bacteria that were infected with T2 bacteriophage that have been labeled with^32 P or^35 S Unfortunately, you forgot to label the tubes and are now uncertain which were^32 P 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 separate 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^ 32 p? Select all tubes that apply. a. Tube 1 b, Tube 2 c. Tube 3 d, Tube 4 e, Tube 5 Heinz Shuster collected the following data on the base composition of ribgrass virus in 1955. On the basis of this information, is the heriditary information of the ribgrass virus or DNA? Is it likely double stranded or single stranded? a. single stranded DNA b double stranded DNA c single stranded RNA d double stranded RNA

Solution

46. ³²P labelled in DNA of Virus. So, it enter in to the bacterial genome and detected in cells. So Tube 1,4 and 5 contains the ³²P.

³⁵S labelled in protein coat of virus. So, it just binds to the outer layer of bacteria and remove by blender. The radioactive ³⁵S detected in supernantant.

47. Single stranded RNA.

A bonds with U = RNA. It wont follows chargaff\'s rule A not equal to U. So it is single stranded RNA.