My teacher asked quite a few questions, but these are the ones with which I am having trouble...I have re-worded them somewhat for clarity. Can anyone please help me! Thank you!

Question

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Methotrexate is a cancer drug that inhibits the enzyme “dihydrofolate reductase,” which is necessary for the production of thymidine (T). Why is it advantageous for cells to become resistant to methotrexate?

To treat cancer, would it be ideal to develop drugs that inhibit the production of additional nucleotides, such as adenosine? Why or why not?

If you are using FISH (fluorescence in situ hybridization) to identify which chromosome contains a gene and where on the chromosome it is located, would you get the most useful information from:
- a sample of dividing cells collected using a cheek swab,
- a sample of non-dividing cells from the upper epidermal layer of skin, or
- a sample of the individual’s gametes?

You want to perform reverse transcriptase PCR, but there isn’t any of the reverse transcriptase enzyme you use left in the lab. You remember that Telomerase has reverse transcriptase activity…would it work for this experiment? Why or why not?

With respect to a eukaryotic genome, discuss how their origins of replication are uniquely identifiable within their genome. With respect to a eukaryotic organism, describe how tissue specific, time specific, or stimulus specific transcription can be achieved through transcription.