22. 23. Some strains of Escherichia coli bacteria have acquired the ability to produce the harmful Shiga toxin, normally produced by Shigella dysenteriae. Which statements best explain why this occurs? Mark all that apply. conjugation between two different species of bacteria allowed both strains of bacteria to express a virulence factor specialized transduction of a specific gene resulted in expression of new traits horizontal gene transfer between different species of bacteria transformation resulted in expression of a virulence factor Bacteria were incubated with aeration in a nutrient medium containing glucose and ribulose (5- carbon sugar), and the following growth curve was made from this culture. Use the graph to match each statement with the correct response. Death phase Lag phase Log phase for ribulose metabolism At time x, a repressible operon was being deactivated and genes encoding enzymes were no longer being expressed A mutation results in substitution of a hydrophobic amino acid for a hydrophilic amino acid in the same position of the active site of a critical anabolic enzyme. This will likely cause which of the following? Mark all that apply. The enzyme will be located in the cell membrane instead of the cytoplasm A shape change in the active site of the enzyme Little or no change in the reaction rate for this enzyme Reduced binding between the enzyme and its substrates.

1. 22.
23.
Some strains of Escherichia coli bacteria have acquired the ability to produce the harmful Shiga
toxin, normally produced by Shigella dysenteriae. Which statements best explain why this
occurs? Mark all that apply. conjugation between two different species of bacteria allowed both
strains of bacteria to express a virulence factor specialized transduction of a specific gene
resulted in expression of new traits horizontal gene transfer between different species of bacteria
transformation resulted in expression of a virulence factor
Bacteria were incubated with aeration in a nutrient medium containing glucose and ribulose (5-
carbon sugar), and the following growth curve was made from this culture. Use the graph to
match each statement with the correct response. Death phase Lag phase Log phase for ribulose
metabolism At time x, a repressible operon was being deactivated and genes encoding enzymes
were no longer being expressed
A mutation results in substitution of a hydrophobic amino acid for a hydrophilic amino acid in
the same position of the active site of a critical anabolic enzyme. This will likely cause which of
the following? Mark all that apply. The enzyme will be located in the cell membrane instead of
the cytoplasm A shape change in the active site of the enzyme Little or no change in the reaction
rate for this enzyme Reduced binding between the enzyme and its substrates