Practice question

“Effects are same for both species” for birth rate and death rate dependency in species 1 and 2 shows. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Interpretation must distinguish absolute population change from a per-capita rate and must state the time interval and population boundary. Age structure, dispersal, environmental variation, and delayed responses can all make observed trajectories depart from a simple model. The remaining alternatives—“Both species have independent death rate”, “Birth rate in species 1 is density-dependent”, “Death rate of species 2 is constant”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Mechanistic support comes from showing how resource limitation, enemies, mate availability, or physiological stress changes demographic performance. A descriptive association alone does not establish regulation or causation. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.