posted by Derek .
In the DNA helix, a ________ (a bicylic nitrogenous base) is always paired with a __________, (a moncyclic nitrogenous base). This occurs because pairing of two of the same kinds of bases would either cause ____________ in the DNA molecule.
a. Pyrimidine, purine, hindrance, instability
b. purine, pyrimidine, hindrance, instability
c. pyrimidine, purine, replication, apoptosis
d. purine, pyrimidine, replication, apoptosis
I think the answer is "B" because apoptosis is the programing of cell death with is not consistant with function of purine and pyrimidine.
B is correct. A very good DNA site is here: