Which type of gene is most likely to be widely expressed in the body of someone who has a superficial scrape?

the gene that controls the production of stem cells
the gene that controls the production of skin cells
the gene that controls the production of red blood cells
the gene that controls the production of cardiac cells

The zone, which exists from a depth of 0 to 600 feet, is home to the majority of ocean life.

Scientific evidence is most likely to be consistent if it is based on data from

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?