Acertain bacterium was cultured for several generations in medium containing 15n, transferred to medium containing 14n, and allowed to complete two rounds of cell division. given that the bacterium’s genome mass is 5.4 fg when grown in 14n media and 5.5 fg when grown in 15n medium, individual bacteria with which of the following genome masses would most likely be isolated from this culture? a.5.4 fg only b.5.4 fg and 5.45 fg c.5.4 fg and 5.5 fg d.5.45 fg only

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.