Population Dynamics Quiz

Population Dynamics

• Populations are groups of organisms of the same species living in the same area at the same time.
• Population size is influenced by birth rates, death rates, immigration, and emigration.
• Exponential growth occurs when a population increases by a constant proportion at each instant in time. Characteristic of populations with ample resources.
• Logistic growth occurs when a population's growth rate slows as it approaches its carrying capacity. This is due to resource limitations.
• Carrying capacity is the maximum population size that a particular environment can sustain indefinitely. Affected by food availability, predation, disease, and habitat space.
• Density-dependent factors affect a population's growth in relation to the population density. Include disease transmission, competition for resources, and predation pressure.
• Density-independent factors affect the population regardless of density. Include natural disasters, temperature fluctuations, and seasonal changes.
• Population fluctuations can be influenced by environmental changes, disease outbreaks, or predator-prey interactions. Fluctuations can be cyclical or erratic.

Community Dynamics

• A community is a group of different populations living and interacting within a particular area.
• Interactions within a community include competition, predation, mutualism, commensalism, and parasitism.
• Competition occurs when two or more species or individuals require the same limited resource, thus reducing the fitness of all.
• Predation occurs when one organism (predator) hunts and consumes another (prey).
• Mutualism is an interaction where both species benefit from the relationship.
• Commensalism is an interaction where one species benefits and the other is neither harmed nor helped.
• Parasitism is an interaction where one species (parasite) benefits at the expense of another (host).
• Keystone species are species that have a disproportionately large effect on their community relative to their abundance. Their removal can significantly alter community structure and biodiversity.
• Succession is the gradual process of change in species composition in a community over time, typically after a disturbance. Primary succession occurs on newly formed habitats, while secondary succession occurs in previously inhabited areas.
• Trophic levels represent different feeding positions in a food web. Producers (plants) form the base of most food webs, followed by primary consumers, secondary consumers, and tertiary consumers.
• Food webs depict the complex interconnected feeding relationships within a community.
• Biodiversity, the variety of life at all levels from genes to ecosystems, is crucial for community stability. Increased biodiversity often leads to greater resilience to disturbances.
• Disturbances, such as fires, floods, or human activities, can alter community structure and provide opportunities for new species to enter or establish themselves. Disturbances can also create varied habitats, leading to increased biodiversity.
• Limiting factors are environmental factors that restrict population growth and influence community composition.
• Community dynamics are complex and influenced by numerous interconnected factors, including availability of resources, species interactions, and environmental conditions.