Leta wants to know what chemical will form a precipitate with sodium chloride (nacl). leta chooses five different chemicals that she can safely mix with nacl. she then places 40 ml of nacl into 5 different beakers. finally, leta pours the different chemicals into the beakers containing nacl. leta observes what happens and records the results. what is the independent variable in leta's experiment?

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Do you think the gene eef1 alpha1 supports cell theory? explain your response.

How would you describe the the organisms in the second row of model 1 that are connected to the parents by a line