Question

part a
which of the following graphs best represents the change in the population of bacteria from the beginning to the end of the video?

graph a: two lines, labeled no mutation (black, steeper) and mutation (red, starts later, less steep), with axes bacteria population size (y) and time (x).
graph b: two lines, labeled mutation (red, steeply curved upward) and no mutation (black, shallowly curved upward), with axes bacteria population size (y) and time (x).
graph c: two lines, labeled no mutation (black, steeply curved upward) and mutation (red, steeper curve starting later), with axes bacteria population size (y) and time (x).
graph d: two lines, labeled no mutation (black, curve peaking then declining) and mutation (red, steeply increasing), with axes bacteria population size (y) and time (x).

part b

Explanation:

In bacterial population dynamics, when a mutation occurs that confers a survival or reproductive advantage (e.g., resistance to an antibiotic, though the context here is general growth advantage), the mutated population should grow exponentially faster than the non - mutated one over time.

• Graph A shows linear growth, which is not typical for bacterial population growth (bacterial growth is usually exponential).
• Graph B: The non - mutated population has a very low growth rate and the mutated one starts growing later but then exponentially. However, in a more typical scenario, both populations start growing from the start, and the mutated one with an advantage should overtake the non - mutated.
• Graph C: Both populations show exponential growth, and the mutated population (with an advantage) grows faster and overtakes the non - mutated one, which is consistent with the idea of a beneficial mutation leading to a higher growth rate (exponential growth, and the mutated population outpaces the non - mutated as time goes on).
• Graph D shows the non - mutated population peaking and then declining, which is not a typical pattern for a simple bacterial population growth with and without a mutation (unless there are external factors like resource depletion, but the question is about the change from beginning to end of the video, likely a scenario of growth with a beneficial mutation). So Graph C best represents the situation where the mutated bacterial population, with a growth advantage, grows exponentially and overtakes the non - mutated population.

Answer:

C. The graph where the "Mutation" (red) curve shows exponential growth and overtakes the "No mutation" (black) curve, representing the mutated bacterial population growing faster (exponentially) and surpassing the non - mutated population over time.