2.2 sg Flashcards
How is population growth determined from birth, death, immigration, and emigration
Birth: The number of babies born in a population will contribute to population growth. If there are more births, the population will increase
Death: The number of deaths in a population reduces the population size. If there are more deaths, the population will decrease.
Immigration: Immigration refers to people moving into a country or region. When individuals immigrate, they add to the population, contributing to population growth.
Emigration: Emigration refers to people leaving a country or region. When individuals emigrate, they reduce the population, potentially slowing population growth or leading to a population
How do you sketch basic graphs showing exponential and logistic growth
Exponential Growth: Population that keeps increasing at a faster and faster rate over time. Like a curve that starts low and then shoots up rapidly without any limit.
Logistic Growth: Population that initially grows exponentially but eventually slows down and levels off. It makes an S-shaped curve, reaching a maximum value that represents the environment’s capacity to sustain it
What do the variables N, N0, r, t, K, dN/dt stand for in the growth models
N: Represents the population size at a specific time. Tells us how many individuals are in the population.
N0: Represents the initial population size at the beginning of the growth model. It’s the starting point for measuring population growth.
r: The growth rate of the population. Tells us how fast the population is increasing or decreasing over time.
t: Represents time. Tells us the specific point in time at which we are measuring the population size.
K: The carrying capacity of the environment. Represents the maximum population size that the environment can sustain in the long run.
dN/dt: Represents the rate of change of the population size with respect to time. Tells us how quickly the population is growing or shrinking at a particular moment.
What are the definitions and examples of density-dependent and density-independent limiting factors
Density-Dependent Limiting Factors: These are influenced by population density and become more significant as the population size increases. They help to regulate population growth and maintain a balance. Examples include competition for resources, predation, disease, and parasitism.
Density-Independent Limiting Factors: These factors will affect population growth regardless of population density. They can have a significant impact on population size, regardless of the number of individuals present. Examples include natural disasters, extreme weather conditions, habitat destruction, and pollution.
