R Programming for Biologists

Teaching the tools to get computers to do cool science

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Strings

Long Strings


For the DNA sequence below determine the following properties and print them to the screen (you can cut and paste the following into your code, it’s a lot longer than you can see on the screen, but just select the whole thing and when you paste it into R you’ll see what it looks like):

dna="ttcacctatgaatggactgtccccaaagaagtaggacccactaatgcagatcctgtgtgtctagctaagatgtattattctgctgtggatcccactaaagatatattcactgggcttattgggccaatgaaaatatgcaagaaaggaagtttacatgcaaatgggagacagaaagatgtagacaaggaattctatttgtttcctacagtatttgatgagaatgagagtttactcctggaagataatattagaatgtttacaactgcacctgatcaggtggataaggaagatgaagactttcaggaatctaataaaatgcactccatgaatggattcatgtatgggaatcagccgggtctcactatgtgcaaaggagattcggtcgtgtggtacttattcagcgccggaaatgaggccgatgtacatggaatatacttttcaggaaacacatatctgtggagaggagaacggagagacacagcaaacctcttccctcaaacaagtcttacgctccacatgtggcctgacacagaggggacttttaatgttgaatgccttacaactgatcattacacaggcggcatgaagcaaaaatatactgtgaaccaatgcaggcggcagtctgaggattccaccttctacctgggagagaggacatactatatcgcagcagtggaggtggaatgggattattccccacaaagggagtgggattaggagctgcatcatttacaagagcagaatgtttcaaatgcatttttagataagggagagttttacataggctcaaagtacaagaaagttgtgtatcggcagtatactgatagcacattccgtgttccagtggagagaaaagctgaagaagaacatctgggaattctaggtccacaacttcatgcagatgttggagacaaagtcaaaattatctttaaaaacatggccacaaggccctactcaatacatgcccatggggtacaaacagagagttctacagttactccaacattaccaggtaaactctcacttacgtatggaaaatcccagaaagatctggagctggaacagaggattctgcttgtattccatgggcttattattcaactgtggatcaagttaaggacctctacagtggattaattggccccctgattgtttgtcgaagaccttacttgaaagtattcaatcccagaaggaagctggaatttgcccttctgtttctagtttttgatgagaatgaatcttggtacttagatgacaacatcaaaacatactctgatcaccccgagaaagtaaacaaagatgatgaggaattcatagaaagcaataaaatgcatgctattaatggaagaatgtttggaaacct"

  1. How long is the sequence?
  2. How many occurences of "gagg" occur in the sequence?
  3. What is the starting position of the first occurrence of "atta"?
  4. What is the GC content of the sequence? The GC content is the percentage of bases that are either G or C (as a percentage of total base pairs). Paste the result as “The GC content of this sequence is XX.XX%” where XX.XX is the actual GC content.