Which of the following can be assumed about a protist that have both flagella and chlorophyll ? a) it must be able to form colonies, and colonies my move around to follow the sun. b) it must be unicellular and it might spend part of its life away from water. c) it must have a nucleus and it might gather food or make food for itself d) it must make its own sugars, and it might use them to make spores for reproduction.

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?