Describe the means by which hershey and chase established that only the dna of a phage enters an e. coli cell. what conclusions did these scientists draw based on these observations?

Harshey and chase labeled T2 bacteriophage with radioactive sulfur and radioactive phosphorus. As DNA contains phosphorus, not protein and protein contain sulfur, not phosphorus, therefore, the presence of radioactivity in cell can determine which is the genetic material .

Then Harshey and Chase infected E.coli with T2 bacteriophage and centrifuged the cell. They found radioactive phosphorus in cell pellet and radioactive sulfur in supernatant.

So by this experiment, they concluded and proved that DNA is the genetic material that gets transfer from one generation to another.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.