Match the following items.
1. rr
2. rr
3. identical alleles
4. unlike alleles
5. rr

heterozygous, dominant cell
homozygous, definition
homozygous, recessive cell
homozygous, dominant cell
heterozygous, definition

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.

How does the color of light affect the germination time (amount time a plant takes to develop) of a radish seed?

Which part of the spine is likely to cause a nerve signal to travel faster? a. backbones b. white matter c. nuclei d. gray matter