Let's break down the problem step by step: ### Step 1: Identify the Template Strand - **Transcription** starts at the +1 site. - The **template strand** is the one that RNA polymerase reads **3' to 5'** to synthesize RNA **5' to 3'**. - In this image: - **Top strand:** 3' to 5' (template) - **Bottom strand:** 5' to 3' (coding/nontemplate) ### Step 2: Find the +1 Site - The **+1 site** is indicated right after "CGC" on the top (template) strand. - So, the template strand at +1: **CAA...** - The coding strand at +1: **GTT...** ### Step 3: Determine the First Four Bases to be Synthesized - **mRNA is complementary to the template strand** and matches the coding strand (except U replaces T). - Write out the next four bases on the template strand starting at +1: ``` Template strand (3' to 5'): C A A T ``` - The mRNA will be synthesized **5' to 3'** and will be **complementary**: - C → G - A → U - A → U - T → A ### Step 4: Write the Final Answer **The first four nucleotides synthesized (5' to 3') are:** ``` 5' GUUA 3' ``` **Final answer:** > **GUUA**