What is the purpose of using multiple control groups in an experiment? a. to provide more work so that you look busy when doing experiments b. to ensure that no experimental subjects escape the maze c. to you identify the substance that you spilled on the floor d. to you determine that your experimental results are valid

of those who start drinking before they're 15 will develop alcohol dependence

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.