Can somebody help me with this??

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?

The lake of the ozarks is a human-made lake, so it collects runoff from coal strip-mining, fertilizers, resort wastewaters, and septic drainages. the average lake temperature is between 10∘c and 21∘c. consider the physical requirements for growth and multiplication that would allow fecal coliforms to “blossom” in the lake of the ozarks. which of the following would accurately describe these organisms? check all that apply. psychrophiles facultative halophiles extremophiles mesophiles hyperthermophiles

The table below shows the elements that mainly comprise each of the four layers of earth: elements in layers layer main elements crust oxygen, silicon mantle iron, magnesium outer core iron, nickel inner core iron which of these elements make up the layer that is 0.2 to 1.1 percent of earth's total diameter?