Biology Chapter 4 - Population Biology Flashcards

Population Biology Key Concepts

• A population consists of organisms of the same species living in a specific area.
• Studying populations involves creating resource-rich environments that reveal growth trends across different species.
• Exponential growth occurs when a population increases rapidly, leading to a significant acceleration in growth rate.
• Populations exhibit a J curve during exponential growth phases, illustrating the rapid increase in numbers.
• The S curve represents a stabilized population graph when growth reaches equilibrium, indicating resources are limited.

Factors Influencing Population Dynamics

• Limiting factors such as food, diseases, and predators restrict population growth.
• Carrying capacity defines the maximum number of organisms an environment can sustain.
• Population growth arises from the condition of having more births than deaths, while decline results from more deaths than births.

Life History Patterns

• Rapid life-history patterns are seen in species like bacteria, which reproduce quickly.
• Slow life-history patterns involve organisms that take longer to mature and reproduce, maintaining steady populations near carrying capacity.

Population Density and Its Effects

• Population density quantifies the number of individuals within a specific area.
• Density-dependent factors (e.g., competition, disease) escalate in impact as population size increases.
• Density-independent factors (e.g., weather events) affect all populations regardless of size.

Population Interaction and Stress

• High predator numbers can lead to a decrease in prey populations.
• Conversely, fewer predators allow prey populations to increase.
• Interactions within populations often display cyclical patterns, especially in predation scenarios.
• Populations facing an inability to cope with high numbers in limited environments may experience stress characterized by aggression, reduced parental care, and lower fertility rates.

Demographics and Human Population

• Demography focuses on human population metrics such as size, density, movement, and rates of birth and death.
• The birth rate measures annual births per 1000 individuals, while the death rate captures output of deaths.
• Immigration refers to individuals moving into a population, while emigration is the departure of individuals.
• A negative population growth rate leads to population decline.
• Doubling time refers to the duration required for a population to double its size.
• Age structure indicates the distribution of a population across various age levels.

Environmental Concerns

• Ecologists are particularly concerned about food supply issues arising from population overload globally.
• Disruptions in wildlife and ecosystems motivate the study of demography and ecology for better management and conservation practices.

Test your knowledge with these flashcards focused on Population Biology from Biology Chapter 4. Each card provides key terms and definitions related to population dynamics and growth trends. Perfect for quick revision and enhancing your understanding of the topic.