Individuals who smoke will have a higher frequency of developing cancer later in life. Which of the following would not be a potential extraneous variable for the stated hypothesis? A. the occurrence of lung cancer in subjects B. exposure to secondhand smoke C. the amount of cigarettes smoked per day by subject D. the number of years as a smoker

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

What are the responsibilities of the region of the brain highlighted below? =+= will rate brainiest =+=

Which best example best demonstrates the importance of having knowledge of evolutionary relationships? a. illustration of a plant b.organ transplantation between species c. blood donation from a human d. do you need sequence of an insect.