Population Growth and Limiting Factors

Vocabulary flashcards summarizing key terms and concepts on population growth, limiting factors, growth phases, and human demographic issues.

Population

A group of organisms of the same species living in the same area at the same time.

Food Supply

Availability of nourishment; abundant food boosts breeding success, whereas shortages cause death or emigration and lower population size.

Predation

Interaction in which one organism (predator) feeds on another (prey); heavy predation can outpace reproduction and shrink population size, often with a time-lagged predator-prey cycle.

Disease

Pathogens spreading within a population; high densities facilitate epidemics that can rapidly reduce numbers.

Use of Contraceptives

Human practice of limiting births through birth-control methods, directly lowering population growth rate.

Limiting Factor

Any environmental condition (e.g., food shortage, predation, disease) that slows population growth and shapes a sigmoid curve.

Sigmoid (S-shaped) Growth Curve

Typical population-growth graph showing lag, log, stationary, and death phases when resources are limited.

Lag Phase

Initial period of slow population increase while organisms mature and acclimatize before rapid reproduction begins.

Log (Exponential) Phase

Stage of unchecked, rapid reproduction where population doubles at a constant rate because limiting factors are absent.

Stationary Phase

Period in which birth rate equals death rate; growth levels off because limiting factors (e.g., food shortage) curb reproduction.

Death Phase

Final stage where deaths exceed births, causing population decline as resources become depleted.

Exponential Growth (No Limiting Factors)

Continued, unrestrained log-phase growth producing a steep, upward curve—observed historically in human populations.

Infant Mortality

Rate of deaths among infants; decreased by improved food supply and medicine, contributing to human population growth.

Life Expectancy

Average lifespan of individuals in a population; rises with better healthcare and nutrition, fueling population expansion.

Developed Country

Nation with advanced economy and healthcare; faces challenges like aging populations and high resource consumption.

Developing Country

Nation with less industrialization and lower income; often experiences rapid population growth with high demand on resources.

Social Implications of Rapid Population Growth

Increased demand for food, water, housing, education, healthcare, energy, and greater environmental pressure and pollution.

Obesity

Condition of excessive body fat; abundant food supplies can raise obesity rates, heightening healthcare demands for heart disease, diabetes, etc.