Why did Meselson and Stahl choose to grow E. coli in broths of nitrogen isotopes? A. The bacteria's phosphate groups would be replaced by the nitrogen.
B. The nitrogen would be incorporated into deoxyribose.
C. The nitrogen would influence bonding between base pairs.
D. The nitrogen would be incorporated into the DNA nucleotides

Ahypothesis that has been tested again and again , with similar results each time may become a law , true or false

The collared lizard is a species found in the desert southwest. male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. your tentative explanation is that male color plays a role in attracting females for mating purposes. you predict that females will preferentially choose brightly colored males over dull-colored ones. to test this prediction, you observed the interactions of female collared lizards with their male counterparts. you selected males that were the same age and size, and that differed only in their coloration pattern. you placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. in 3 instances, the females did not mate with either type. create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. on the y-axis, plot the frequency with which each type of male was chosen by females. using this graph, answer the following question(s). is it reasonable to conclude (i. e., is it supported by the data) that female collared lizards prefer more brightly colored male lizards over dull-colored males?

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this