What is phagocytosis in regard to the immune system of humans? A. the process by which the immune system responds to an antigen by producing antibodies against it

B. the process by which basophils are activated by antigens that are bound to antibodies

C. the process by which eosinophils release a cytotoxin to kill pathogens

D. the process by which neutrophils ingest a bacterium

What volume of a 0.25 m solution can be made using 0.55 moles of ca(oh)2

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

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?