Textbook Question
In eukaryotes, what allows only certain genes to be expressed in different types of cells?
Ch. 19 - Control of Gene Expression in Eukaryotes
Freeman8th EditionBiological ScienceISBN: 9780138276263
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Table of contents
- Ch. 1 - Biology: The Study of Life13
- Ch. 2 - Water and Carbon: The Chemical Basis of Life14
- Ch.3 - Protein Structure and Function10
- Ch.4 - Nucleic Acids and the RNA World10
- Ch. 5 - An Introduction to Carbohydrates10
- Ch. 6 - Lipids, Membranes, and the First Cells11
- Ch. 7 - Inside the Cell10
- Ch. 8 - Energy and Enzymes: An Introduction to Metabolism10
- Ch. 9 - Cellular Respiration and Fermentation11
- Ch. 10 - Photosynthesis12
- Ch. 11 - Cell-Cell Interactions12
- Ch. 12 - The Cell Cycle8
- Ch. 13 - Meiosis12
- Ch. 14 - Mendel and the Gene23
- Ch. 15 - DNA and the Gene: Synthesis and Repair15
- Ch. 16 - How Genes Work16
- Ch. 17 - Transcription, RNA Processing, and Translation16
- Ch. 18 - Control of Gene Expression in Bacteria16
- Ch. 19 - Control of Gene Expression in Eukaryotes12
- Ch. 20 - The Molecular Revolution: Biotechnology, Genomics, and New Frontiers15
- Ch. 21 - Genes, Development, and Evolution12
- Ch. 22 - Evolution by Natural Selection16
- Ch. 23 - Evolutionary Processes13
- Ch. 24 - Speciation15
- Ch. 25 - Phylogenies and the History of Life13
- Ch. 26 - Bacteria and Archaea15
- Ch. 27 - Diversification of Eukaryotes16
- Ch. 28 - Green Algae and Land Plants16
- Ch. 29 - Fungi18
- Ch. 30 - An Introduction to Animals9
- Ch. 31 - Protostome Animals15
- Ch. 32 - Deuterostome Animals17
- Ch. 33 - Viruses16
- Ch. 34 - Plant Form and Function16
- Ch. 35 - Water and Sugar Transport in Plants16
- Ch. 36 - Plant Nutrition13
- Ch. 37 - Plant Sensory Systems, Signals, and Responses16
- Ch. 38 - Flowering Plant Reproduction and Development16
- Ch. 39 - Animal Form and Function17
- Ch. 40 - Water and Electrolyte Balance in Animals16
- Ch. 41 - Animal Nutrition16
- Ch. 42 - Gas Exchange and Circulation16
- Ch. 43 - Animal Nervous Systems16
- Ch. 44 - Animal Sensory Systems16
- Ch. 45 - Animal Movement11
- Ch. 46 - Chemical Signals in Animals16
- Ch. 47 - Animal Reproduction and Development16
- Ch. 48 - The Immune System in Animals16
- Ch. 49 - An Introduction to Ecology15
- Ch. 50 - Behavioral Ecology16
- Ch. 51 - Population Ecology16
- Ch. 52 - Community Ecology20
- Ch. 53 - Ecosystems and Global Ecology17
- Ch. 54 - Biodiversity and Conservation Ecology18
Chapter 19, Problem 5b
Compare and contrast the items in each pair:
(b) promoter-proximal elements and the operator of the lac operon
Verified step by step guidance1
Understand the role of promoter-proximal elements: These are regulatory sequences located near the promoter of a gene. They are important for the initiation of transcription and can be bound by transcription factors to increase or decrease the rate of transcription.
Understand the role of the operator in the lac operon: The operator is a specific DNA sequence in the lac operon that acts as a binding site for the repressor protein. When the repressor is bound to the operator, it prevents RNA polymerase from transcribing the genes necessary for lactose metabolism.
Compare the location of promoter-proximal elements and the operator: Promoter-proximal elements are located upstream of the promoter, whereas the operator is located downstream of the promoter, within the operon itself.
Contrast the function of promoter-proximal elements and the operator: Promoter-proximal elements generally regulate the transcription of a wide range of genes by interacting with transcription factors, while the operator specifically regulates the transcription of genes in the lac operon by interacting with the lac repressor.
Consider the regulatory mechanisms: Promoter-proximal elements can be involved in both positive and negative regulation depending on the transcription factors that bind to them, whereas the operator primarily functions in negative regulation by blocking transcription when the repressor is bound.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Promoter-Proximal Elements
Promoter-proximal elements are regulatory DNA sequences located near the promoter of a gene. They play a crucial role in the initiation of transcription by providing binding sites for transcription factors, which can enhance or repress the transcription of the associated gene. These elements are essential for the precise regulation of gene expression in eukaryotic cells.
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02:37
Proximal Tubule
Operator of the Lac Operon
The operator is a specific DNA sequence within the lac operon in prokaryotes, particularly E. coli, that acts as a binding site for the repressor protein. When the repressor binds to the operator, it prevents RNA polymerase from transcribing the downstream genes involved in lactose metabolism. This mechanism allows the cell to regulate gene expression in response to the presence or absence of lactose.
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07:06The Lac Operon
Gene Regulation in Prokaryotes vs. Eukaryotes
Gene regulation in prokaryotes, such as the lac operon, often involves operons where genes are transcribed together and regulated by a single operator. In contrast, eukaryotic gene regulation involves complex interactions with promoter-proximal elements and multiple transcription factors, allowing for more precise and varied control of gene expression. This difference reflects the complexity and diversity of eukaryotic cellular functions.
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03:47Introduction to Eukaryotic Gene Regulation
Related Practice
Textbook Question
What is alternative splicing?
a. Phosphorylation that leads to different types of post-translational regulation
b. mRNA processing that leads to different combinations of exons being spliced together
c. Folding that leads to proteins with alternative conformations
d. The outcome of regulatory proteins that leads to changes in the life span of an mRNA
Textbook Question
Compare and contrast the items in each pair:
(a) enhancers and the E. coli CAP binding site
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Textbook Question
Compare and contrast the items in each pair:
(c) general transcription factors and sigma.
Textbook Question
Imagine discovering a loss-of-function mutation in a eukaryotic gene. You determine the gene's nucleotide sequence from the start site for transcription to the termination point of transcription and find no differences from the wild-type sequence. Explain where you think the mutation might be and how the mutation might be acting.
Textbook Question
The following statements are about the control of chromatin condensation. Select True or False for each.
T/F Reducing histone acetylase activity is likely to decrease gene transcription.
T/F Mutations that reduce the number of positively charged amino acids on histones should promote open chromatin.
T/F Chromatin remodeling complexes add chemical groups to histones.
T/F Adding an inhibitor of DNA methylation is likely to reduce gene transcription.