DNA Structure exercise - Free Printable

Problem Analysis:

The image depicts a DNA strand and its complementary RNA strand. The task is to identify the sequence of the RNA strand based on the given DNA sequence and fill in the missing parts.

#### Key Observations:
1. DNA Strand (Left Side):
- The DNA sequence is shown as `5' GATC 3'`.
- The bases are labeled as follows:
- Green: Adenine (A)
- Yellow: Thymine (T)
- Purple: Guanine (G)
- Red: Cytosine (C)

2. RNA Strand (Right Side):
- The RNA strand is being synthesized complementary to the DNA strand.
- The RNA strand is oriented from `3'` to `5'`.
- The bases in RNA are represented by blue pentagons, and the sugar-phosphate backbone is shown with orange lines.

3. Base Pairing Rules:
- In DNA-RNA transcription:
- Adenine (A) pairs with Uracil (U) in RNA.
- Thymine (T) pairs with Adenine (A) in RNA.
- Guanine (G) pairs with Cytosine (C) in RNA.
- Cytosine (C) pairs with Guanine (G) in RNA.

4. Orientation:
- The DNA strand is oriented from `5'` to `3'`.
- The RNA strand is synthesized in the opposite direction, from `3'` to `5'`.

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Solution Approach:

1. Identify the DNA Sequence:
- The DNA sequence is `5' GATC 3'`.

2. Determine the Complementary RNA Sequence:
- Using the base pairing rules:
- G (Guanine) pairs with C (Cytosine).
- A (Adenine) pairs with U (Uracil).
- T (Thymine) pairs with A (Adenine).
- C (Cytosine) pairs with G (Guanine).
- Therefore, the complementary RNA sequence is `3' CGAU 5'`.

3. Fill in the Missing Parts:
- The RNA strand is already partially drawn, but the bases need to be identified.
- The RNA strand should read `3' CGAU 5'` when completed.

4. Label the RNA Bases:
- The RNA bases are represented by blue pentagons.
- The corresponding bases are:
- Cyan: Cytosine (C)
- Gray: Guanine (G)
- Light Blue: Adenine (A)
- Orange: Uracil (U)

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Final Answer:

The completed RNA strand is `3' CGAU 5'`. The bases in the RNA strand are:
- First base (closest to `3'`): Cytosine (C)
- Second base: Guanine (G)
- Third base: Adenine (A)
- Fourth base (closest to `5'`): Uracil (U)

Thus, the RNA sequence is:
\[
\boxed{3' \text{CGAU} 5'}
\]