Which density-dependent factor involves the struggle between organisms to survive in a habitat with limited resources and often leads to population decline due to starvation?

• A. Predation
• B. Pollination
• C. Parasitism
• D. Competition

Answer: (D)

Competition centers on organisms vying for scarce resources like food, water, and space. As a population grows, those resources become more limited per individual, so per-capita intake drops. When resources are insufficient, many individuals may not obtain enough energy, leading to starvation, lower survival, and reduced reproduction, which can drive a population downward. Predation involves being eaten by other organisms and isn’t the same mechanism as resource scarcity inside the habitat. Pollination is about a plant–pollinator interaction and doesn’t describe competition for limited resources. Parasitism can affect hosts and may scale with host density, but the scenario specifically highlights the struggle to survive under limited resources, which is the hallmark of competition.