9.2 Study Guide

Question 1

How population growth is determined from birth, death, immigration, and emigration?

Answer 1

As the population gets more dense: births go down, deaths increase, immigration decreases, and emigration increases.

Question 2

Where population growth is highest in exponential and logistic growth?

Answer 2

In exponential growth - highest at its tipping point, since it keeps increasing
In logistic growth - highest at half carrying capacity

Question 3

What the variables N, N0, r, t, K, dN/dt stand for in the growth models?

Answer 3

N - population size
N0 - population size at time
r - Per rate of growth
t - time
K - carrying capacity
dN/dt - population growth rate

Question 4

Definitions and examples of density-dependent and density-independent limiting factors?

Answer 4

Density-dependent - Effect is dependent on the density of the population (disease, competition for water).
Density- independent - Effect is not related to the density of the population (drought, food).

Question 5

How exponential and logistic growth models change when r, N, or K change and why?

Answer 5

Exponential growth models - the graph will stay the same (keeping increasing).
Logistic growth models - the graph will begin to level off.