What are the 4 layers of our atmosphere in order?

Drag each label to the correct location on the table. each label can be used more than once. decide whether each statement describes saturated fat, unsaturated fat, or both saturated and unsaturated fats.

Question#29: why does the tropical ocean have a greater temperature range than the temperate ocean?

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?