Question

complete the paragraph to summarize how an rna molecule is created. first, a section of the dna molecule is
. then, rna nucleotides are brought in to pair with the dna nucleotides. according to the rules of complementary base pairing,
pairs with thymine, and guanine pairs with
. but rna contains the nitrogenous base uracil instead of
. uracil pairs with
.
nitrogenous bases:
a - adenine
t - thymine
g - guanine
c - cytosine
u - uracil
diagram of dna/rna structure with hydrogen bonds, ribose sugar, etc.

Explanation:

• The first step in RNA synthesis (transcription) is the unzipping of the DNA molecule to expose the template strand.
• Complementary base pairing rules: Adenine (A) pairs with Thymine (T) in DNA - DNA pairing, but in DNA - RNA pairing, A in DNA pairs with U in RNA, and T in DNA pairs with A in RNA. Guanine (G) pairs with Cytosine (C) in both DNA - DNA and DNA - RNA pairing.
• RNA has uracil (U) as a nitrogenous base instead of thymine (T) which is found in DNA. Uracil pairs with adenine (A) following the base - pairing rules.

Answer:

1. First blank: "unzipped" (The DNA molecule must be unzipped to expose the nucleotide sequence for RNA synthesis.)
2. Second blank: "adenine" (According to complementary base pairing, adenine (A) pairs with thymine (T) in DNA - RNA pairing, adenine in RNA pairs with thymine in DNA, and in RNA - RNA or DNA - RNA base pairing for transcription, adenine pairs with thymine (in DNA template) and uracil (in RNA). But in the context of DNA to RNA transcription, the RNA nucleotide's adenine pairs with DNA's thymine. Wait, actually, when RNA is synthesized from DNA, the RNA nucleotide's base pairs with DNA's base: adenine (A) in DNA pairs with uracil (U) in RNA, thymine (T) in DNA pairs with adenine (A) in RNA, guanine (G) in DNA pairs with cytosine (C) in RNA, and cytosine (C) in DNA pairs with guanine (G) in RNA. Wait, maybe I messed up. Let's correct: The rules of complementary base pairing for DNA - RNA transcription: DNA's A pairs with RNA's U, DNA's T pairs with RNA's A, DNA's G pairs with RNA's C, DNA's C pairs with RNA's G. So the second blank (the base that pairs with thymine) is adenine (because DNA's T pairs with RNA's A).
3. Third blank: "cytosine" (Guanine (G) pairs with cytosine (C) in complementary base pairing.)
4. Fourth blank: "thymine" (RNA contains uracil (U) instead of thymine (T) which is present in DNA.)
5. Fifth blank: "adenine" (Uracil (U) pairs with adenine (A) in RNA - DNA or RNA - RNA base pairing. In transcription, U in RNA pairs with A in DNA template.)