BIO 340 Holechek Exam 1
Questions & Answers
2026/2027 | Arizona State
University | Updated Edition
(Rationales)
Document Overview
This document provides 15 questions with correct answers and detailed
rationales for molecular biology. It is an updated edition from Arizona State
University, suitable for studying, reviewing course material, or preparing for
certification. This resource offers a comprehensive overview of key concepts with
explanations to solidify understanding.
100% Accurate Questions and Answers
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Verified Answers · Detailed Rationales · 15 Questions · September 2026
BIO 340 Holechek Exam 1 Questions & Answers 2026/2027 | Arizona State University | Updated Edition (Rationales) - Practice Questions Page 0
, Topics Covered
Section 1: DNA Structure and Composition Q 1-5
Questions covering dNA Structure and Composition concepts.
Section 2: Translation and Protein Synthesis Q 6-11
Questions covering translation and Protein Synthesis concepts.
Section 3: DNA Replication and Transcription Q 12-13
Questions covering dNA Replication and Transcription concepts.
Section 4: Molecular Biology Experiments Q 14-15
Questions covering molecular Biology Experiments concepts.
Questions
QUESTION 1 OF 15
Given a genome with 16% Thymine, how much of the genome is cytosine?
Correct Answer: 34%
Rationale: In a double-stranded DNA genome, Adenine (A) always pairs with Thymine (T), and Guanine (G) always
pairs with Cytosine (C), meaning A=T and G=C. If Thymine constitutes 16% of the genome, then Adenine also
constitutes 16%, leaving 68% for Guanine and Cytosine combined. Since Guanine and Cytosine are present in equal
amounts, Cytosine comprises half of this remaining percentage, which is 34%.
QUESTION 2 OF 15
Match the following DNA coding strand sequence to the correct mRNA sequence. DNA
sequence:
5' - ATG—ATC—TCG—TAA - 3'
Correct Answer: 5'- AUG—AUC—UCG—UAA - 3'
Rationale: 5'- AUG—AUC—UCG—UAA - 3', the DNA coding strand serves as a template for mRNA synthesis, with
uracil (U) replacing thymine (T) to form complementary base pairs. Therefore, the DNA sequence 5'-ATG-ATC-TCG-
TAA-3' directly corresponds to the mRNA sequence 5'-AUG-AUC-UCG-UAA-3' where A pairs with U, T pairs with A,
and G pairs with C. This direct correspondence, with the substitution of U for T, dictates the resulting mRNA sequence.
QUESTION 3 OF 15
The strands that make of the DNA double helix are running?
Correct Answer: Anti-Parallel
Rationale: Anti-Parallel, meaning they run in opposite directions with respect to their 5' and 3' ends. This orientation
is crucial for DNA replication and transcription mechanisms. The 5' end of one strand aligns with the 3' end of the
complementary strand, and vice versa.
BIO 340 Holechek Exam 1 Questions & Answers 2026/2027 | Arizona State University | Updated Edition (Rationales) - Practice Questions Page 0