Textbook Question
Which of the following is true of a codon?
a. It never codes for the same amino acid as another codon.
b. It can code for more than one amino acid.
c. It can be either in DNA or in RNA
d. It is the basic unit of protein structure
Ch. 17 - Gene Expression: From Gene to Protein
Urry12th EditionCampbell BiologyISBN: 9785794169850
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Table of contents
- Ch. 1 - Evolution, the Themes of Biology, and Scientific Inquiry8
- Ch. 2 - The Chemical Context of Life8
- Ch. 3 - Water and Life6
- Ch. 4 - Carbon and the Molecular Diversity of Life9
- Ch. 5 - The Structure and Function of Large Biological Molecules9
- Ch. 6 - A Tour of the Cell6
- Ch. 7 - Membrane Structure and Function6
- Ch. 8 - An Introduction to Metabolism6
- Ch. 9 - Cellular Respiration and Fermentation10
- Ch. 10 - Photosynthesis7
- Ch. 11 - Cell Communication7
- Ch. 12 - The Cell Cycle11
- Ch. 13 - Meiosis and Sexual Life Cycles10
- Ch. 14 - Mendel and the Gene Idea14
- Ch, 15 - The Chromosomal Basis of Inheritance6
- Ch. 16 - The Molecular Basis of Inheritance9
- Ch. 17 - Gene Expression: From Gene to Protein9
- Ch. 18 - Regulation of Gene Expression10
- Ch. 19 - Viruses6
- Ch. 20 - DNA Tools and Biotechnology7
- Ch. 21 - Genomes and Their Evolution8
- Ch. 22 - Descent with Modification: A Darwininan View of Life6
- Ch. 23 - The Evolution of Populations5
- Ch. 24 - The Origin of Species6
- Ch. 25 - The History of Life on Earth8
- Ch. 26 - Phylogeny and the Tree of Life8
- Ch. 27 - Bacteria and Archaea6
- Ch. 28 - Protists7
- Ch. 29 - Plant Diversity I: How Plants Colonized Land7
- Ch. 30 - Plant Diversity II: The Evolution of Seed Plants6
- Ch. 31 - Fungi5
- Ch. 32 - An Overview of Animal Diversity4
- Ch. 33 - An introduction to Invertebrates6
- Ch. 34 - The Origin and Evolution of Vertebrates7
- Ch. 35 - Vascular Plant Structure, Growth, and Development10
- Ch. 36 - Resource Acquisition and Transport in Vascular Plants8
- Ch. 37 - Soil and Plant Nutrition11
- Ch. 38 - Angiosperm Reproduction and Biotechnology8
- Ch. 39 - Plant Responses to Internal and External Signals8
- Ch. 40 - Basic Principles of Animal Form and Function8
- Ch. 41 - Animal Nutrition7
- Ch. 42 - Circulation and Gas Exchange7
- Ch. 43 - The Immune System5
- Ch. 44 - Osmoregulation and Excretion6
- Ch. 45 - Hormones and the Endocrine System8
- Ch. 46 - Animal Reproduction9
- Ch. 47 - Animal Development8
- Ch. 48 - Neurons, Synapses, and Signaling6
- Ch. 49 - Nervous Systems8
- Ch. 50 - Sensory and Motor Mechanisms5
- Ch. 51 Animal Behavior6
- Ch. 52 - An Introduction to Ecology and the Biosphere7
- Ch. 53 - Population Ecology9
- Ch. 54 - Community Ecology9
- Ch. 55 - Ecosystems and Restoration Ecology8
- Ch. 56 - Conservation Biology and Global Change6
Chapter 17, Problem 4
Which of the following is true of RNA processing? (A) Exons are cut out before mRNA leaves the nucleus. (B) Nucleotides are added at both ends of the RNA. (C) Ribozymes may function in the addition of a 5′ cap. (D) RNA splicing adds a poly-A tail to the mRNA.
Verified step by step guidance1
Identify the correct statements about RNA processing, which involves modifications to the pre-mRNA transcript in eukaryotic cells.
Understand that exons are the coding regions of the RNA that remain in the sequence to be expressed, while introns are the non-coding regions that are removed during RNA splicing.
Recognize that a 5′ cap is added to the 5′ end of the RNA and a poly-A tail is added to the 3′ end, but these modifications involve specific enzymes rather than ribozymes.
Recall that RNA splicing involves the removal of introns and the joining of exons, and does not add a poly-A tail to the mRNA.
Evaluate each option based on the known processes of RNA processing: splicing, 5′ capping, and poly-A tail addition.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
RNA Processing
RNA processing refers to the modifications that pre-mRNA undergoes before it becomes mature mRNA. This includes the removal of non-coding sequences called introns and the joining together of coding sequences known as exons. Additionally, RNA processing involves the addition of a 5' cap and a poly-A tail, which are crucial for mRNA stability and translation.
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04:19
1) RNA Processing
Exons and Introns
Exons are the coding regions of a gene that are retained in the final mRNA product, while introns are non-coding regions that are removed during RNA splicing. Understanding the distinction between exons and introns is essential for grasping how mRNA is prepared for translation, as only exons contribute to the protein-coding sequence.
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08:442) RNA Splicing Creates Mature mRNA
5' Cap and Poly-A Tail
The 5' cap is a modified guanine nucleotide added to the beginning of the mRNA transcript, which protects the mRNA from degradation and assists in ribosome binding during translation. The poly-A tail, a sequence of adenine nucleotides added to the 3' end, also enhances mRNA stability and regulates its translation efficiency. Both modifications are critical for the proper functioning of mRNA in protein synthesis.
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04:191) RNA Processing
Related Practice
Textbook Question
In eukaryotic cells, transcription cannot begin until
a. The two DNA strands have completely separated and exposed the promoter.
b. Several transcription factors have bound to the promoter.
c. The 5′ caps are removed from the mRNA.
d. The DNA introns are removed from the template.
Textbook Question
The anticodon of a particular tRNA molecule is
a. Complementary to the corresponding mRNA codon
b. Complementary to the corresponding triplet in rRNA
c. The part of tRNA that bonds to a specific amino acid
d. Catalytic, making the tRNA a ribozyme
Textbook Question
Which component is directly involved in translation?
A. RNA polymerase
B. ribosome
C. spliceosome
D. DNA
Textbook Question
Using Figure 17.6, identify a 5′→3′ sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys.
a. 5′-UUUCCCAAA-3′
b. 5′-GAACCCCTT-3′
c. 5′-CTTCGGGAA-3′
d. 5′-AAACCCUUU-3′
Textbook Question
Which of the following mutations would be most likely to have a harmful effect on an organism?
a. A deletion of three nucleotides near the middle of a gene
b. A single nucleotide deletion in the middle of an intron
c. A single nucleotide deletion near the end of the coding sequence
d. A single nucleotide insertion downstream of, and close to, the start of the coding sequence