Which of the following statements about the
mass number of an atom is incorrect?
select one:
a. it has a unit defined as a dalton.
b. on earth, it equals the atomic
weight.
c. it equals the number of electrons
in an atom.

Which chemical equation is unbalanced? which chemical equation is unbalanced

Iwill mark brainliest and all that sha-bang. what is the function of the endocrine system? a. control longer term response in the body. b. transmit messages throughout the body. c. remove waste from the body. d. all of the above

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?