How are genes related to dna?
genes are sections of dna that program the amino acid sequences of proteins.
genes are monomers that are joined by hydrolysis to make dna.
o genes are monomers that are joined by dehydration synthesis to make dna.
genes are proteins that bind molecules of dna together to make amino acids,

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?