Chapter 27: Population Growth and Regulation

ecosystem

all the organisms in an area along with their non living environment

ecology

the study of how these organisms interact with one another and their environment

population

consists of all the members of a particular species that live in a specific area

1. natural increase

2. net migration

changes in population size result from:
1.
2.

net migration

the difference between immigration (migration into population) and emigration (migration out)

positive, negative

the natural increase is ______ if births exceed deaths, or _______ if deaths exceed births

growth rate

the change in the population size per unit time
b (birth rate) - d (death rate) = r

population growth per unit time

multiply growth rate by population size to find this

biotic potential

maximum rate at which population can increase

boom and bust cycles

when rapid population growth is followed by a sudden, massive die off

logistic growth

occurs when populations stabilize

density independent factors

limit populations regardless of density; prevent from exceeding carrying capacity

density dependent factors

have larger effects as population density increases

parasite

an organism that lives in or on a larger organisms, called its host, feeding on it and harming it

1. interspecific competition

2. intraspecific competition

two major forms of competition:
1.
2.

interspecific competition

individuals of different species compete

intraspecific competition

competition between individuals of the same species

roughly triangular

if adults are having more children than are needed to replace themselves, the population is above RLF and is rapidly expanding; the age diagram will be _______ ________

straight sides

if the adults have just the number of children needed to replace themselves, the population is at RLF; the age diagram will have ______ ______

narrowed at the base

in a shrinking population, the reproducing adults have fewer children than are required to replace themselves; the age diagram will be ______ __ ____ ____

replacement level fertility (RLF)

if parents produce just the number of children required to replace themselves, this number is ________ _____ _________