Question 4

which of these is a case of selective breeding?

to increase the production of milk in a herd of milk cows, the highest producing cows were chosen as the mothers.

over time, more milk cows at the diary farm began to produce larger amounts of milk.

a gene was identified that increased milk production. this gene was added to calves in the womb.

the genome of a group of cows was analyzed to identify the gene for milk production.

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.