Question

You are a graduate student at the University of Iowa and working as a teaching assistant for a freshman introductory biology course. Two of your students have come to you with a ques- tion about the sequence of an mRNA transcribed from a gene. The original DNA sequence from which the mRNA was transcribed reads: TGACGATCGTA. The students were asked to provide the sequence of bases in the mRNA and came up with the following mRNA sequence: ACTGCTAGCAT. They are confused because their answer does not match the answer in the book. Briefly explain the very common mistake they made and what the correct sequence is.

Answer 1

Answer: The corret DNA sequence is ACUGCUAGCAU.

Explanation: The common mistake that they make is, they forget to replace thymine with uracil as a base pair of Adenine. During DNA transcription Thymine is replaced by Uracil in production of messenger RNA. Uracil is a de-mythylated form of thymine and requires less energy to produce.