An RNA molecule has the following percentages of bases: \( \mathrm{A}=23 \%, \mathrm{U}=42 \%, \mathrm{C}=21 \% \), and \( \mathrm{G}=14 \% \). © Macmillan Learning Is this RNA single-stranded or double-stranded? How can you tell? double-stranded, because it has approximately equal percentages of A and C double-stranded, because it has a higher percentage of \( U \) than \( A, C \), or \( G \) single-stranded, because it does not have equal percentages of G and C single-stranded, because it has approximately equal percentages of \( A \) and \( C \) What would be the percentage of bases in the template strand of the DNA that contains the gene for this RNA? \( A= \) \( \square \) \( \mathrm{U}= \) \( \square \) \[ \mathrm{T}= \] \( \square \) \[ \mathrm{C}= \] \( \square \) \[ \% \] (1) \( G= \) \( \square \) \%

To determine whether the RNA molecule is single-stranded or double-stranded, we can analyze the base composition. 1. **Base Pairing Rules**: In double-stranded nucleic acids, the bases pair according to specific rules: Adenine (A) pairs with Uracil (U) in RNA, and Cytosine (C) pairs with Guanine (G). For a double-stranded RNA, the percentages of A and U should be approximately equal, and the percentages of C and G should also be approximately equal. 2. **Given Percentages**: - \( A = 23\% \) - \( U = 42\% \) - \( C = 21\% \) - \( G = 14\% \) 3. **Analysis**: - The percentage of A (23%) is not equal to the percentage of U (42%). - The percentage of C (21%) is not equal to the percentage of G (14%). - Since the percentages of A and U, as well as C and G, are not approximately equal, this indicates that the RNA is **single-stranded**. Thus, the correct answer is: - **Single-stranded, because it does not have equal percentages of G and C.** --- Next, we need to determine the percentage of bases in the template strand of the DNA that contains the gene for this RNA. 1. **Base Pairing in DNA**: In DNA, the base pairing rules are: - A pairs with T (Thymine) - C pairs with G 2. **Calculating the DNA Template Strand Percentages**: - The percentage of A in RNA corresponds to the percentage of T in the DNA template strand. - The percentage of U in RNA corresponds to the percentage of A in the DNA template strand (since U is replaced by T in DNA). - The percentage of C in RNA corresponds to the percentage of G in the DNA template strand. - The percentage of G in RNA corresponds to the percentage of C in the DNA template strand. 3. **Calculations**: - \( A_{DNA} = U_{RNA} = 42\% \) - \( T_{DNA} = A_{RNA} = 23\% \) - \( C_{DNA} = G_{RNA} = 14\% \) - \( G_{DNA} = C_{RNA} = 21\% \) Now, we can summarize the percentages for the DNA template strand: - \( A = 42\% \) - \( U = 0\% \) (since DNA does not contain U) - \( T = 23\% \) - \( C = 21\% \) - \( G = 14\% \) Thus, the final answers are: - \( A = 42\% \) - \( U = 0\% \) - \( T = 23\% \) - \( C = 21\% \) - \( G = 14\% \)