DNA is composed of repeating structural units called . is the five-carbon sugar found in DNA. 3 components of a nucleotide are labeled. Part A is a phosphate with 1 double-bond and single-bonds to 3 Oxygen molecules. Part B is a sugar with 5 carbon molecules. Part D is made up of nitrogen molecules.

To maintain asepsis when administering an injection, all parts of the syringe can be handled except the:

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?

Produce proteins by following coded instructions that come from the nucleus of the cell.