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2. Consider the following aligned 13-mer DNA sequences: GGGAAATGCGTCA TGTTCATGGC

ID: 3811 • Letter: 2

Question

2. Consider the following aligned 13-mer DNA sequences:
GGGAAATGCGTCA
TGTTCATGGCTTG
GAAGCATGACTCT
GAAATATGAGGGA
GAATCATGGAATG
ATAAGATGGCCCA
TGGAAATGGCCGC
CAAAGATGCGCTG
AATTAATGACATT
TTTGCATGAGGCG

How many of each bases appear at each position?
#A :_ _ _ _ _ _ _ _ _ _ _ _ _
#C :_ _ _ _ _ _ _ _ _ _ _ _ _
#G :_ _ _ _ _ _ _ _ _ _ _ _ _
#T :_ _ _ _ _ _ _ _ _ _ _ _ _

If these bases appeared at random each should appear 2.5 times ineach position. At
which positions are the same bases present 5 or more times?

What would you suggest is the consensus sequence?
_ _ _ _ _ _ _ _ _ _ _ _ _

Explanation / Answer


            1     2     3      4     5      6    7      8     9    10    11   12    13             G    G     G    A      A    A     T    G     C    G     T    C      A
            T    G      T    T     C     A     T    G     G    C    T      T     G
            G    A      A    G    C     A     T    G     A    C    T     C      T             G    A      A   A     T     A      T    G   A    G    G     G     A
            G    A      A   T     C     A      T    G     G   A     A    T      G
            A    T      A   A     G     A      T    G     G   C     C    G     C
            C    A     A   A     G     A     T     G     C    G    C    T    G
            A    A    T    T      A    A      T     G     A    C    A     T     T
            T    T      T    G     C    A       T    G     A   G     G    C     G       #A :2_ 5       5_ 4_     2 _ 9_      0 _ 0 _ 4 _ 1_   2_    0_   2    
      #C :1_ 0_     0_   0 _  4_   0_    0_    0 _ 4 _   2_  3 _   3    1
      #G :4_2_     1_   2_    2_   0_     0_   9_  3_    4 _2_     2_ 4_
             #T :2_ 2_     3_  3_     3 _ 0_     9_   0_  0_   0 _  3_     4_  2_

      At position 2 and 3 thebase A is present 5 times and at position 6 it ispresent 9 times.       At position 8 base base G is present 9 times and at position 7 base T ispresent 9 times.       The consensus sequence isa way of representing the multiple sequence alignment.       The consensus sequence forthis may be as:       N(CCC)NNATG(T)N(A)N