Giraffes evolved over many generations to have long necks. giraffes that had longer necks were more likely to survive than giraffes with shorter necks because they had better access to food. this is an example of .

If there are 350 trout found in 200 square feet of a pond measuring 1000 square feet what is the estimated trout population of the pond? a. 1350 b. 1550 c. 1750 d. 2000

Which of the following types of reactions would decrease the entropy within a cell? a. dehydration reaction, b. hydrolysis, c. respiration, d. digestion, e. catabolism.

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?