Chapter 5 5-1 How Populations Grow Characteristics of Populations Geographic Distribution the area inhabited by a population – Population Density number of individuals per unit area – Growth Rate an increase or decrease of the number of individuals in a population – over time Population Growth/Decline A population can grow when its birthrate is greater than its death rate Immigration movement of individuals into an area – Populations can increase Animals maybe searching for mates or food Emigration movement of individuals out of an area – Populations can decrease Animals leave to find mates or food Exponential Growth Under ideal conditions with unlimited resources a population will grow exponentially resulting in a population explosion Exponential growth is characterized by a J-shaped In nature exponential growth does not continue in a population for very long As resources become less available, the growth of a population slows or stops Logistic Growth Occurs when a population’s growth slows or stops following a period of exponential growth Logistic growth is characterized by a S-shaped What prevents the world from being overrun with all kinds of living things?
Chapter 5 5-1 How Populations Grow Characteristics of Populations Geographic Distribution – the area inhabited by a population Population Density – number of individuals per unit area Growth Rate – an increase or decrease of the number of individuals in a population over time Population Growth/Decline A population can grow when its birthrate is greater than its death rate Immigration – movement of individuals into an area Populations can increase Animals maybe searching for mates or food Emigration – movement of individuals out of an area Populations can decrease Animals leave to find mates or food Exponential Growth Under ideal conditions with unlimited resources a population will grow exponentially resulting in a population explosion Exponential growth is characterized by a J-shaped In nature exponential growth does not continue in a population for very long As resources become less available, the growth of a population slows or stops Logistic Growth Occurs when a population’s growth slows or stops following a period of exponential growth Logistic growth is characterized by a S-shaped What prevents the world from being overrun with all kinds of living things?
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