C. because stimuli is how your body responds to something, and in this case, someone's heart rate increases WHEN their blood oxygen drop. Do you see how it responds? ;-)
Answer:
Equal amounts of DNA contain equal proportions of nitrogenous bases.
Explanation:
According to Chargaff's rule, the nitrogenous base pairs (Purines and pyrimidines) have an equal ratio (1:1) in the DNA of all the organisms. More precisely, the amount of adenine is equal to thymine and the amount of guanine is equal to cytosine in the DNA of all the organism. A-T base pair has two H-bonds while G-C base pair has three H-bonds.
An adaptation-----------------------
