Which of these would best explain why the microbial population begins to decrease after a period of time?
Responses
A organisms moved away to find new matesorganisms moved away to find new mates
B extra food was introduced into the areaextra food was introduced into the area
C the graph actually never shows the population decreasingthe 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
D organisms began to die as the population was larger than could be supported by the limiting factors
D - organisms began to die as the population was larger than could be supported by the limiting factors.
The best explanation for why the microbial population begins to decrease after a period of time would be option D: organisms began to die as the population was larger than could be supported by the limiting factors. This option suggests that the population size reached a point where the available resources and conditions could no longer sustain the large number of organisms, leading to a decline in the population.
To arrive at this answer, one needs to consider the concept of limiting factors. Limiting factors are elements or conditions in an environment that restrict the growth, abundance, or distribution of a population. Examples of limiting factors for microbial populations can include the availability of nutrients, space, sunlight, moisture, or temperature. When the population exceeds the carrying capacity of these limiting factors, it can result in decreased survival and reproductive rates, ultimately leading to a decrease in population size.
To make an informed choice, one must analyze the other options:
A) "organisms moved away to find new mates" is not a likely reason for a population decrease. While movement and migration can impact population dynamics, it is unlikely that the entire microbial population would move away simultaneously to find new mates.
B) "extra food was introduced into the area" could actually have the opposite effect on the population. The availability of extra food would usually contribute to population growth rather than decrease.
C) "the graph actually never shows the population decreasing" indicates that the population does not decrease at all. However, if the question suggests that the microbial population does decrease, this option would be incorrect.
Therefore, option D is the most reasonable and scientifically accurate explanation for the decrease in the microbial population after a period of time.