Name: Period:
DNA Base Pairing Worksheet
There are base pairing rules for writing complimentary nucleic acid strands:
In DNA, A pairs with T and C pairs with G
In RNA, A pairs with U, instead of T
#1-5: Write the complimentary DNA strand for each given strand of DNA:
C G T A A G C G C T A A T T A
T C T T A A A T G A T C G A T
A A T G A A T A G C T A G C T
G G C A T T C G C G A T C A T
C G T T A G C A T G C T T C A
#6-10: Now write the mRNA strand for the given DNA strand:
A T G T C G C T G A T A C T G
G A A G C G A T C A G T T A C
A A T G A A T A G C T A G C T
G G C A T T C G C G A T C A T
C G T T A G C A G A T T A C A
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Name: Period:
Draw a line between the codons for each strand of mRNA:
11. AGGUCAUGCAUGGGCAUGCAU
12. AGAGAUUCAGCUAGCACGAUA
13. GUCAUCGAUCGAUCGGAUGCC
14. UUUCAGUCAGCUAGCGAUCGU
15. CUAAUGUGGAUCCUGAACGCU
Use the codon chart (p.4) for #16-20. Translate the amino acid sequence
for the given mRNA strand. Remember that codons are 3 base pairs long.
Below each codon, write the 3-letter abbreviation for the corresponding
amino acid.
A U G C A C U G U C C U U U C
G A G A U C U G G U U G G A A
A G C G U A U U A A C G U A U
A G U C G A U C G A U G C G G
G U C G C U G A U A G C U A U
21. Transcribe the following DNA strand. Then translate the mRNA strand
you wrote to into the amino acid sequence:
C G T A A G C G C T A A T T A
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Name: Period:
22. Work backwards! Convert the following amino acid sequence to RNA
and then to DNA. Is there more than one possible solution? The 3-letter
amino acid code is provided.
Met Arg Ser Ala Thr
23. Work backwards again! Convert the following amino acid sequence to
RNA and then to DNA. Is there more than one possible solution? The 1-
letter amino acid code is provided.
D A N C E
24. How many possible codon sequences are there?
25. How many amino acids are there?
26. What pattern(s) do you notice about amino acids with more than one
codon sequence? In which letter position in the codon (first, second, or
third) is the most variability present? Why do you think that is?
27. What letters of the alphabet are missing from the 1-letter amino acid
abbreviations?
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Name: Period:
Bonus! What is the longest word you can find using only the letters
available in the 1-letter amino acid abbreviations? For extra credit (one
point per correctly solved letter), write the word and then solve the
corresponding RNA and DNA sequences for the word (as in #23).
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