Sci Week 8

• Population


  A group of organisms of the same species that live in a certain area
• Carrying capacity


  The number of individuals who can be supported in a given area within natural resource limits, and without degrading the natural social, cultural and economic environment for present and future generations
• Population growth


  1. Exponential growth when resources are unlimited

  2. Logistic growth when resources are limited
• Density-independent factors


  • Limiting factors that can stop population growth such as natural disasters, temperature, sunlight and human activities
• Density-dependent factors


  • Factors that come into play when population reaches a certain number of organisms, such as lack of resources (food, shelter, water)
• When resources are unlimited, populations exhibit exponential growth, resulting in a J-shaped curve
• When resources are limited, populations exhibit logistic growth, where population expansion decreases as resources become scarce and levels off when the carrying capacity of the environment is reached, resulting in an S-shaped curve
• Before the population reaches its carrying capacity, it experiences a period of rapid growth called exponential population growth
• During exponential population growth, there are plenty of resources available for all organisms, so more births are recorded than deaths
• Biodiversity describes how varied are life forms in different ecosystems