If cpr is not performed, how many minutes will elapse before the brain becomes damaged from lack of oxygen?

a. 1
b. 2
c. 4
d. 10

Which best explains why there are 64 possible codons in the genetic code and only 20 amino acids that make protiens of living organisms on earth

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

Explain how the political influence of african americans leaders became weaker.