8.[04.05) Which statement best describes an atom? (1 point)
Protons and neutrons grouped in a specific pattern
Protons and electrons spread around randomly
A group of protons and neutrons that are surrounded by electrons
A ball of electrons and neutrons surrounded by protons

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.

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment

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