DNA Base Pairing Worksheet featuring exercises to write complementary DNA strands and mRNA sequences based on given DNA sequences.

Problem Overview:

The task involves writing complementary DNA strands for given DNA sequences and then converting the DNA strands into mRNA strands. The base pairing rules are as follows:
- DNA Base Pairing Rules:
- A pairs with T
- T pairs with A
- C pairs with G
- G pairs with C

- RNA Base Pairing Rule (for mRNA):
- In RNA, A pairs with U instead of T.

Solution Approach:

1. Complementary DNA Strands:
- For each given DNA strand, write its complementary strand by replacing each base with its pair according to the DNA base pairing rules.
- Reverse the order of the bases in the complementary strand because DNA strands are antiparallel.

2. mRNA Strands:
- Convert the given DNA strands into mRNA strands by replacing all T's with U's. The sequence remains in the same order as the original DNA strand.

Step-by-Step Solution:

#### Part 1: Complementary DNA Strands

1. Given DNA Strand: CGTAAGCGCTAATA
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: CGTAAGCGCTAATA
- Complementary: TAATTAGCGCTTACG
- Answer: TAATTAGCGCTTACG

2. Given DNA Strand: TCTTAAATGTGCATC
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: TCTTAAATGTGCATC
- Complementary: GATGCAACATTAAAGA
- Answer: GATGCAACATTAAAGA

3. Given DNA Strand: AATGAATAGCTAGCTT
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: AATGAATAGCTAGCTT
- Complementary: AAGCTACTATTCATT
- Answer: AAGCTACTATTCATT

4. Given DNA Strand: GGCAITCGCATCATG
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: GGCAITCGCATCATG
- Complementary: CATGATGCGAATGCC
- Answer: CATGATGCGAATGCC

5. Given DNA Strand: CGTTAGCATGCTTCAT
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: CGTTAGCATGCTTCAT
- Complementary: ATGAAGCATGCTAACG
- Answer: ATGAAGCATGCTAACG

6. Given DNA Strand: ACTAACGGTAGCTAGC
- Complementary strand:
- Replace A with T, T with A, C with G, G with C.
- Reverse the order:
- Original: ACTAACGGTAGCTAGC
- Complementary: GCTAGCTACCGTTAGT
- Answer: GCTAGCTACCGTTAGT

#### Part 2: mRNA Strands

7. Given DNA Strand: ATGTCGCTGATACTGT
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: ATGTCGCTGATACTGT
- mRNA: AUGUCGCUGAUACUGU
- Answer: AUGUCGCUGAUACUGU

8. Given DNA Strand: GAAGCGATCAGTTAGC
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: GAAGCGATCAGTTAGC
- mRNA: GAAGCGAUCAGUUAUGC
- Answer: GAAGCGAUCAGUUAUGC

9. Given DNA Strand: AATGAATAGCTAGCTT
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: AATGAATAGCTAGCTT
- mRNA: AAUGAAUAGCUGAGCUU
- Answer: AAUGAAUAGCUGAGCUU

10. Given DNA Strand: GGCATTCGCGATCATG
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: GGCATTCGCGATCATG
- mRNA: GGCAUUUGCGAUCACUG
- Answer: GGCAUUUGCGAUCACUG

11. Given DNA Strand: CGTTAGCATGCTTCAT
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: CGTTAGCATGCTTCAT
- mRNA: CGUUAUGCAUCUUCAU
- Answer: CGUUAUGCAUCUUCAU

12. Given DNA Strand: ACTAACGGTAGCTAGC
- mRNA strand:
- Replace all T's with U's.
- Sequence remains the same as the original DNA strand.
- Original: ACTAACGGTAGCTAGC
- mRNA: ACUAACGGUAGCUGAGC
- Answer: ACUAACGGUAGCUGAGC

Final Answers:

1. Complementary DNA: TAATTAGCGCTTACG
2. Complementary DNA: GATGCAACATTAAAGA
3. Complementary DNA: AAGCTACTATTCATT
4. Complementary DNA: CATGATGCGAATGCC
5. Complementary DNA: ATGAAGCATGCTAACG
6. Complementary DNA: GCTAGCTACCGTTAGT

7. mRNA: AUGUCGCUGAUACUGU
8. mRNA: GAAGCGAUCAGUUAUGC
9. mRNA: AAUGAAUAGCUGAGCUU
10. mRNA: GGCAUUUGCGAUCACUG
11. mRNA: CGUUAUGCAUCUUCAU
12. mRNA: ACUAACGGUAGCUGAGC

Final Boxed Answers:
\[
\boxed{
\begin{array}{ll}
1. & \text{TAATTAGCGCTTACG} \\
2. & \text{GATGCAACATTAAAGA} \\
3. & \text{AAGCTACTATTCATT} \\
4. & \text{CATGATGCGAATGCC} \\
5. & \text{ATGAAGCATGCTAACG} \\
6. & \text{GCTAGCTACCGTTAGT} \\
7. & \text{AUGUCGCUGAUACUGU} \\
8. & \text{GAAGCGAUCAGUUAUGC} \\
9. & \text{AAUGAAUAGCUGAGCUU} \\
10. & \text{GGCAUUUGCGAUCACUG} \\
11. & \text{CGUUAUGCAUCUUCAU} \\
12. & \text{ACUAACGGUAGCUGAGC} \\
\end{array}
}
\]