Question

Resource availability affects populations of organisms in an ecosystem. Other factors such as predators, disease, and weather can also cause changes to populations as well. Evaluate the graph showing the population of moose over time. Infer possible explanations for changes in the population? Choose ALL that apply.
Responses
A The moose had abundant food and limited predators in 1970.The moose had abundant food and limited predators in 1970.
B The carrying capacity of the moose population is around 600.The carrying capacity of the moose population is around 600.
C The carrying capacity of the moose population is around 800.The carrying capacity of the moose population is around 800.
D There was most likely an increase in predators from 1990 - 2000.There was most likely an increase in predators from 1990 - 2000.
E In 1990, some sort of catastrophic event caused the death of more than half the moose.

Answer 1

Selected: A, C, and E.

Brief reasoning:
- A: True — the early rise in the population suggests resources were abundant and mortality (predation) was low enough for growth.
- C: True — the population levels off near ~800 before the crash, which indicates a carrying capacity around 800.
- E: True — the sudden, large drop around 1990 (more than half) is consistent with a catastrophic event (disease, severe weather, human activity, etc.).

Why not the others:
- B is incorrect because the plateau is nearer 800, not 600.
- D is unlikely because the sharp crash occurs at ~1990 (suggesting a sudden event) rather than a gradual decline from increased predation over 1990–2000.