Chargaff discovered that in dna extracted from organisms, the amounts of guanine and cytosine are roughly the same, and the amounts of adenine and thymine are roughly the same. why was this discovery important?

a. the amounts of each nitrogenous base in dna proved that dna is copied before cells divide. b. the base pairing of adenine to thymine and of guanine to cytosine was a key piece of information in elucidating the structure of dna. c. the amount of thymine can't be more than the amount of cytosine in a given strand of dna. d. the amounts of each nitrogenous base in dna determines the function of the dna

B. The base pairing of adenine to thymine and of guanine to cytosine was a key piece of information in elucidating the structure of DNA.

Explanation:

Erwin Chargaff, a biochemist proposed a rule called Chargaff’s rule that states that s that the amounts of the purine bases are equal to pyrimidine bases.  Thus, the amount of adenine is equal to the amount of thymine, and the amount of cytosine is equal to the amount of guanine. Further, he states that the pairing of bases is fixed. Adenine always pairs with thymine and guanine is always pairs with cytosine.

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

explanation: