The following question refers to the figure.
In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E. coli population.

E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions of this experiment, E. coli generation times in the experimental lines and low-glucose conditions should ________.
A) be the same as in the typical environment
B) be faster than in the typical environment
C) be slower than in the typical environment
D) increase over time in the experimental cells

Question

The following question refers to the figure.
In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor)E. coli population.

E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions of this experiment, E. coli generation times in the experimental lines and low-glucose conditions should ________.
A) be the same as in the typical environment 
B) be faster than in the typical environment 
C) be slower than in the typical environment 
D) increase over time in the experimental cells

Quizplus · Accepted Answer

The populations of E. coli were grown in low-glucose conditions for 20,000 generations. With a limited glucose supply, the E. coli would have had to adapt their metabolism to utilize alternative carbon sources, which could result in a slower growth rate compared to typical conditions where glucose is abundant. Therefore, under the conditions of this experiment, E. coli generation times in the experimental lines and low-glucose conditions should be slower than in the typical environment (choice C).

The Following Question Refers to the Figure