PLEASE DON'T PUT A LINK Which two scientists used x-ray diffraction to try to determine the 3-dimensional structure of DNA?

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.

Kate is studying the transformation from unicellular to multicellular organisms. which metaphor is the most appropriate to apply to the map of the timeline.

Select the correct answer. what does the hardy-weinberg principle relate to? a. chances of survival of an organism b. frequency of alleles in a population c. natural selection in a species d. causes of evolution among organisms