10. Read the help on string objects and attempt the following for dna strings. (a) replace all occurances of 'a' with 'A' and revert back. (b) return capitalized version. 4 (c) join two dna strings. 11. Modify the last but two problem to return a list of dna counts, e.g [6,4,2,4] Key Ideas: append method of list objects. 12. Read the help on the find method of strings to prepare a list of all positions of 'a' in the dna. Hint: >>>dna='gcatgactattccttgac' >>>dna.find('a') >>>2 >>>dna.find('a',3) >>>5 >>>dna.find('a',6) >>>8 >>>dna.find('a',9) 16 >>>dna.find('a', 17) -1 Key Ideas: Preparing logical conditions from flag variables, append method of list objects. 13. Write a function to look for non ambiguous restriction sites in the supplied data file(dna.dat) for EcoRI, BamHI, Hind