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Module 4 Lesson 1 Progress Check

Prompt

Read Module 4 Lesson 1 (p.77, 80-85).

Answer the "Check Your Progress" questions (p.85 #2, 4, 5) and submit your answers here. You may write out your answers in your biology journal and take a picture, or you may type out your answers for submission.

*For #5, briefly describe your design of the experiment in a 2-3 sentences (you do NOT need to write out a full procedure)

Response

  1. Summarize the concepts of carrying capacity and limiting factors, and their effects on reproductive patterns.
    1. Carrying capacity refers to the maximum population size of a particular species that an environment can support indefinitely, given the food, habitat, water, and other resources available. When a population surpasses its carrying capacity, it leads to a decline in the resources, which can in turn decrease the population until it stabilizes at or below \(K\).
    2. Limiting factors are environmental factors that restrict the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem. They can be biotic (e.g., competition, predation, disease) or abiotic (e.g., temperature, pH, light, nutrient availability). As the population grows, limiting factors become more influential.
    3. Effects on reproductive patterns could be shown when populations are well below the carrying capacity. Then, they have exponential growth, but as they approach the carrying capacity, growth slows and may stabilize or decline due to limiting factors. This can lead to a logistic growth pattern. Reproductive rates may decrease when resources are scarce, and competition becomes intense.

  2. Analyze the impact a nonnative species might have on a native species in terms of population dynamics.

    When a foreign species shows up in a new place, it can throw off the balance of the local ecosystem. These newcomers often snatch up resources, leaving the locals struggling. Worse still, they might bring new diseases that the native species aren't equipped to handle. Some nonnative species even change the landscape in ways that locals can't adapt to. There's also the chance of them mixing with the locals, blurring the unique genetic lines. All in all, introducing a new species can cause a lot of unexpected chaos for those already living there.

  3. Design an experiment that you could perform to determine which population growth model applies to fruit fly populations.

    • Introduce a known number of fruit flies into a closed environment with a set amount of resources (food, space). Monitor the fruit fly population size over time, collecting data at regular intervals.
    • Introduce different groups of fruit flies into multiple environments with varying resource amounts to determine the effects of resource availability on growth patterns.
    • Plot the population size over time to determine if the growth is exponential (J-shaped curve) or logistic (S-shaped curve). Comparing the curves with different resource availabilities will help determine which growth model is applicable.