Your Text Discusses the Evolution of Antibiotic-Resistant M

question 25

Multiple Choice

Your text discusses the evolution of antibiotic-resistant M.tuberculosis bacteria in a patient.Researchers discovered that the strain of M.tuberculosis taken from the dead patient has a point mutation in the rpoB gene that codes for part of the RNA polymerase enzyme.This mutant form of RNA polymerase does not normally function as well as the more common form,but a commonly used antibiotic called rifampin does not affect the mutant rpoB.A researcher places M.tuberculosis isolated from the patient a year before death (no rpoB mutation) in cell cultures with M.tuberculosis isolated from the dead patient (with rpoB mutation) .Half the cell cultures contain just standard nutrients,and the other cell cultures contain rifampin in addition to the standard nutrients.After many cell generations,the researcher finds that

• A)very few M.tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation,but almost all of the M.tuberculosis in the cell cultures with rifampin carry the rpoB mutation.
• B)almost all M.tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation,but very few of the M.tuberculosis in the cell cultures with rifampin carry the rpoB mutation.
• C)very few M.tuberculosis in any of the cell cultures carry the rpoB gene mutation.
• D)almost all of the M.tuberculosis in both types of cell cultures carry the rpoB mutation.
• E)a mix of both M.tuberculosis strains thrive in the standard cell cultures,but no living bacteria can be found in the cell cultures that contain rifampin.

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Definitions:

Homozygous

Having two identical alleles.

Allele

One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

XYY Sex Chromosomal

Refers to a genetic condition in which a male has an extra Y chromosome, often associated with tall stature but typically without significant physical or mental disabilities.

Language Development

The way in which toddlers begin to make sense of and communicate in language throughout their early years.