menu
bartleby
search
close search
Hit Return to see all results
close solutoin list

Carrying the Cystic Fibrosis Allele Offer Protection from Typhoid Fever Epithelial cells that lack the CFTR protein cannot take up bacteria by endocytosis. Endocytosis is an important part of the respiratory tract’s immune defenses against common Pseudomonas bacteria, which is why Pseudomonas infections of the lungs are a chronic problem in cystic fibrosis patients. Endocytosis is also the way that Salmonella typhi bacteria (shown at right) enter cells of the gastrointestinal tract, where internalization of this bacteria can result in typhoid fever. Typhoid fever is a common worldwide disease. Its symptoms include extreme fever and diarrhea, and the resulting dehydration causes delirium that may last several weeks. If untreated it kills up to 30 percent of those infected. Around 600,000 people, most of whom are children, die annually from typhoid fever. Gerald Pier and his colleagues compared the uptake of S. typhi by different types of epithelial cells: those homozygous for the normal allele, and those heterozygous for the ΔF508 allele associated with CF. (Cells that are homozygous for the mutation do not take up any S. typhi bacteria .) Some of their results are shown in FIGURE 13.16 . FIGURE 13.16 Effect of the ΔF508 mutation on the uptake of three different strains of Salmonella typhi bacteria by epithelial cells. Regarding the Ty2 strain of S. typhi , about how many more bacteria were able to enter normal cells than cells heterozygous for the ΔF508 allele?

BuyFindarrow_forward

Biology: The Unity and Diversity o...

15th Edition
Cecie Starr + 3 others
Publisher: Cengage Learning
ISBN: 9781337408332

Solutions

Chapter
Section
BuyFindarrow_forward

Biology: The Unity and Diversity o...

15th Edition
Cecie Starr + 3 others
Publisher: Cengage Learning
ISBN: 9781337408332
Chapter 13, Problem 1DAA
Textbook Problem
220 views

Carrying the Cystic Fibrosis Allele Offer Protection from Typhoid Fever Epithelial cells that lack the CFTR protein cannot take up bacteria by endocytosis. Endocytosis is an important part of the respiratory tract’s immune defenses against common Pseudomonas bacteria, which is why Pseudomonas infections of the lungs are a chronic problem in cystic fibrosis patients. Endocytosis is also the way that Salmonella typhi bacteria (shown at right) enter cells of the gastrointestinal tract, where internalization of this bacteria can result in typhoid fever.

Typhoid fever is a common worldwide disease. Its symptoms include extreme fever and diarrhea, and the resulting dehydration causes delirium that may last several weeks. If untreated it kills up to 30 percent of those infected. Around 600,000 people, most of whom are children, die annually from typhoid fever.

Gerald Pier and his colleagues compared the uptake of S. typhi by different types of epithelial cells: those homozygous for the normal allele, and those heterozygous for the ΔF508 allele associated with CF. (Cells that are homozygous for the mutation do not take up any S. typhi bacteria.) Some of their results are shown in FIGURE 13.16.

Chapter 13, Problem 1DAA, Carrying the Cystic Fibrosis Allele Offer Protection from Typhoid Fever Epithelial cells that lack , example  1

Chapter 13, Problem 1DAA, Carrying the Cystic Fibrosis Allele Offer Protection from Typhoid Fever Epithelial cells that lack , example  2

FIGURE 13.16 Effect of the ΔF508 mutation on the uptake of three different strains of Salmonella typhi bacteria by epithelial cells.

Regarding the Ty2 strain of S. typhi, about how many more bacteria were able to enter normal cells than cells heterozygous for the ΔF508 allele?

Summary Introduction

To explain: The number of Ty2 strain of Salmonella typhi that was able to enter normal cells than cells heterozygous for the ΔF508 allele.

Introduction: An allele is the modification of the gene. Salmonella typhi is the causative bacteria of typhoid. Cystic fibrosis (CF) is a genetic disorder caused due to the inability of the cell to perform endocytosis due to a mutation in the CFTR gene. Cystic fibrosis affects the lungs, intestine, liver, and kidneys. Endocytosis is a phenomenon where the cell takes up molecules by engulfing with its membrane. The S. typhi exploits this mechanism to infect the intestinal cell and causes diarrhea. The cells that are homozygous for this CFTR mutation cannot perform endocytosis, and the S. typhi cannot infect those individuals.

Explanation of Solution

Scientist G along with his colleagues studied the uptake of S. typhi by two types of epithelial cells:

  • Cells that are homozygous for the normal alleles.
  • Cells that are heterozygous for ΔF508 allele associated with CF and the normal alleles.

Cells that are homozygous for the mutant allele do not take up S. typhi; therefore, those cells were not chosen. A bar graph was drawn with three strains of S. typhi on the X-axis, and the number of bacteria internalized by both types of cells in the Y-axis.

Approximately, 600,000 S. typhi entered the normal cells that are homozygous for the normal alleles.

Approximately, 80,000 S. typhi entered the mutated cells that are heterozygous for ΔF508 allele associated with CF and normal alleles.

Therefore, the number of times more S. typhi entered normal cells than heterozygous cells can be calculated as follows:

Number oftimes moreS. typhi entered normal cells=60000080000=7.5

Conclusion

Therefore, about 7.5 times more S. typhi entered the normal cells.

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Chapter 13 Solutions

Biology: The Unity and Diversity of Life (MindTap Course List)
Show all chapter solutions
add

Additional Science Textbook Solutions

Find more solutions based on key concepts
Show solutions add
Trabecular bone readily gives up its minerals whenever blood calcium needs replenishing. T F

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

What are sister chromatids?

Human Heredity: Principles and Issues (MindTap Course List)

How are sediments studied?

Oceanography: An Invitation To Marine Science, Loose-leaf Versin

A source delivers an AC voltage of the form = 98.0 sin 80t. where is in volts and t is in seconds, to a capac...

Physics for Scientists and Engineers, Technology Update (No access codes included)