Question

microbe population
number of microbes
time
part b
which of these would best explain why the microbial population begins to decrease after a period of time?
a organisms moved away to find new mates
b extra food was introduced into the area
c the graph actually never shows the population decreasing
d organisms began to die as the population was larger than could be supported by the limiting factors

Explanation:

To determine why the microbial population decreases, we analyze each option:

• Option A: Moving for mates doesn't directly cause population decrease.
• Option B: Extra food would likely increase population, not decrease it.
• Option C: The graph shows a decrease, so this option's claim that it never decreases is false.
• Option D: When the population exceeds the carrying capacity (supported by limiting factors like resources), organisms die, leading to a population decrease. This matches the scenario.

Answer:

D. organisms began to die as the population was larger than could be supported by the limiting factors