What effect do enzymes have on chemical reactions?

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

How can active reading strategies you? o a. they can you get into better physical shape. o b. they can you read fewer science articles. o c. they can you understand what you read. o d. they can you avoid reading altogether.

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?