To which two external stimuli do the roots of a plant respond?

Which of the following statements best describes the relationship between the environment and human health? a. the environment is the only factor that affects human health. b. many aspects of the environment can have an impact on human health. c. human health is impacted by changes in climate. d. the environment has no impact on human health. select the best answer from the choices provided

Which element forms the basis of all organic organisms a carbon b oxygen c hydrogen d nitrogen

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?