Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 14, Problem 8P
Recently, scientists tested the possibility that human gut bacteria may play a role in determining body weight.
The study subjects were four sets of twins (one set of identical twins and three sets of fraternal twins), where one twin was of normal weight and the other was obese. Samples of their gut bacteria were collected and transplanted into bacteria-free mice. Mice with the different bacterial transplants were all fed the same diet and monitored over the course of about one month. For each of the four twin pairs, the mice with the bacteria from the obese twin gained significantly more weight and fat than the mice transplanted with the bacteria from the normal twin.
a. | What would you conclude about the relationship between the human gut microbiome and body weight? |
b. | Why were twins used in the study? |
c. | Do the results of this study mean that human genes (genes in the nuclei of human cells) do not play a role in body weight and fat content? Explain. |
d. | Mice are coprophagic, meaning that they eat feces. How could you test whether a certain bacterial species associated with leanness or obesity could successfully invade the gut microbiome of an animal in which that bacterial species was not previously found? |
e. | One problem with using bacteria-free mice in experiments such as this is that the mouse gut is not equivalent to the human gut as a bacterial host: Different bacterial species thrive in mice and humans. Explain how this fact could affect the experiment discussed in this problem. |
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Chapter 14 Solutions
Genetics: From Genes to Genomes
Ch. 14 - Choose the phrase from the right column that best...Ch. 14 - The unicellular, rod-shaped bacterium E. coli is 2...Ch. 14 - Now that the sequence of the entire E. coli K12...Ch. 14 - Bacterial genomes such as that of E. coli...Ch. 14 - List at least three features of eukaryotic genomes...Ch. 14 - Describe a mechanism by which a gene could move...Ch. 14 - High salt concentrations tend to cause protein...Ch. 14 - Recently, scientists tested the possibility that...Ch. 14 - A recent metagenomic study analyzed the...Ch. 14 - Linezolid is a new type of antibiotic that...
Ch. 14 - A liquid culture of E. coli at a concentration of...Ch. 14 - Pick out the medium i, ii, iii, or iv onto which...Ch. 14 - This problem concerns Fig. 14.14, which...Ch. 14 - In two isolates one is resistant to ampicillin,...Ch. 14 - E. coli cells usually have only one copy of the F...Ch. 14 - In E. coli, the genes purC and pyrB are located...Ch. 14 - DNA sequencing of the entire H. influenzae genome...Ch. 14 - Genes encoding toxins are often located on...Ch. 14 - a. You want to perform an interrupted-mating...Ch. 14 - In Problem 19, do you think that most of the...Ch. 14 - One issue with interrupted-mating experiments such...Ch. 14 - Prob. 22PCh. 14 - Starting with an F- strain that was prototrophic...Ch. 14 - You can carry out matings between an Hfr and F...Ch. 14 - Genome sequences show that some pathogenic...Ch. 14 - Generalized and specialized transduction both...Ch. 14 - This problem highlights some useful variations of...Ch. 14 - A researcher has a Trp auxotrophic strain of E....Ch. 14 - Streptococcus parasanguis is a bacterial species...Ch. 14 - The sequence at one end of one strand of the...Ch. 14 - Scientists who study amino acid biosynthesis...Ch. 14 - Suppose that you could obtain radioactively...Ch. 14 - Prob. 34PCh. 14 - Some scientists are trying to engineer...
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