Suppose a mutation occurs in the DNA section in problem 17.89, and the first base in the parent chain, adenine, is replaced by guanine.
b. Using the new strand that results from this mutation, write the order of bases in the altered mRNA.

Verified step by step guidance

1. Identify the original DNA sequence from problem 17.89 and note the specific base sequence in the parent chain before the mutation.
2. Understand the mutation: The problem states that adenine (A) in the parent chain is replaced by guanine (G). Modify the DNA sequence accordingly to reflect this change.
3. Recall the base-pairing rules for DNA to RNA transcription: In RNA, adenine (A) pairs with uracil (U), thymine (T) pairs with adenine (A), cytosine (C) pairs with guanine (G), and guanine (G) pairs with cytosine (C).
4. Using the altered DNA strand (after the mutation), transcribe the sequence into mRNA by replacing each DNA base with its complementary RNA base according to the base-pairing rules.
5. Write out the final sequence of the altered mRNA strand, ensuring that the mutation is reflected in the sequence.

Key Concepts

DNA Mutation

A DNA mutation is a change in the nucleotide sequence of an organism's DNA. This can occur due to various factors, including environmental influences or errors during DNA replication. In this case, the mutation involves the substitution of adenine (A) with guanine (G), which can lead to changes in the resulting protein if it occurs in a coding region.

Transcription

Transcription is the process by which the genetic information in DNA is copied into messenger RNA (mRNA). During transcription, RNA polymerase reads the DNA template strand and synthesizes a complementary RNA strand. The order of bases in the mRNA is determined by the sequence of the DNA template, meaning that any mutations in the DNA will directly affect the mRNA sequence produced.

Base Pairing Rules

Base pairing rules dictate how nucleotides pair in DNA and RNA. In DNA, adenine pairs with thymine (A-T) and guanine pairs with cytosine (G-C). However, during transcription, adenine pairs with uracil (A-U) in RNA. Understanding these rules is essential for determining the sequence of mRNA that results from a mutated DNA strand, as they guide the correct pairing of bases.