How would scientists know if populations were increasing or decreasing over time?

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?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Why did rutherford say that bombarding atoms with particles was like "playing with marbles" what