Need help on AP Biology essay about DNA. Can you please help? I'll give 10 points for most helpful answer?

Question

Here is the prompt: Scientists seeking to determine which molecule is responsible for the transmission of characteristics from one generation to the next knew that the molecule must (1) copy itself precisely, (2) be stable but able to be changed, and (3) be complex enough to determine the organisms's phenotype.

Explain how DNA meets each of the three criteria stated above.

Select one of the criteria stated above and describe experimental evidence used to determine that DNA is the hereditary material.

WHAT I HAVE so far:

The DNA has to produce its own copies through DNA replication.

Stability od DNA, which is achieved by many hydrogen bonds between DNA strands and ability to be changed, basepairs undergoing changes, leading to mutation.

WHAT ELSE??

Answer 1

As you know, the structure of DNA is a double helix of polymers that are hydrogen bonded between the A, C, G, and T bases.  As you also know, this structure was described by Watson and Crick in a famous paper in 1953.  Their last sentence (or maybe second to last sentence according to some web sites) is famous in its own regard:  "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material."

In fact, the structure of DNA immediately suggests answers to 1, 2, and 3 above, and your answers seem correct to me.  The structure of DNA, due to its base pairing, does suggest that it could be replicated by copying of the individual strands.  It is stable, as predicted from the structure and tested experimentally, but can be altered by changing the order of the bases.  It can form extremely long molecules with an endless variation of the sequence of bases, so even without knowing the genetic code, one can infer that it is capable of transmitting a large amount of information.

As for the experiments, I am not sure what to suggest, so I won't.  However, you have the advantage of knowing that these experiments were actually done to understand these exact issues.  So, I would suggest looking through a textbook to see how the issues were answered and incorporating similar info into your answer.

I hope this helps, but be aware that my answers might not be complete.  Good luck.