The first heart sound is made by blood moving to the atria
blood moving to the ventricles
opening of the valve between the atria and the ventricles
closing of the valve between the atria and the ventricles

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants. d. selecting individuals at random.

Which of the following statements most accurately describes convergent evolution? the process in which two similar species evolve separately from each other and share similar characteristics the process in which a single species evolves into two or more new species the process in which two entirely different species evolve in response to each other the process in which two different species evolve separately from each other but still share similar characteristics

Is there any solid scientific evidence that humans have been cloned?