Chapter 44 Ecology Test Flashcards
Group of one species of an organism in a specific area
Population
Physical location where an organism lives
Habitat
The role that organisms play or their job in the environment
Niche
All organisms in a given area
Community
The study of the relationship between an organism and its environment
Ecology
Number of individuals of a species in a unit area or volume
Population density
Describe how individuals are scattered throughout the habitat
Dispersion patterns
Types of dispersion patterns
Random
Uniform
Clumped/uneven
Dispersion pattern that has randomly scattered individuals throughout the habitat
Random
Dispersion pattern that has individuals evenly dispersed
Uniform
Dispersion pattern that has individuals clustered together
Clumped/uneven
Study of factors that influence changes in a population size
Population dynamics
Entering a population
Immigration
Leaving a population
Emigration
The number of new individuals produced per unit time
Birth rate
Refers to distribution of the age classes
Age structure
Age classes
Pre reproductive
Reproductive
Post reproductive
In humans, occurs before puberty
Pre reproductive class
Age at which individuals can reproduce
Reproductive class
Age group that cannot reproduce
Post reproductive class
Age structure diagrams
Growing population
Stable population
Declining population
Has a large pre reproductive class
Growing population
All 3 classes are about the same size
Stable population
Most members are reproductive and post reproductive
Declining population
Number of individuals dying per unit time
Death rate
A graph of the proportion of surviving individuals at any given age
Survivorship curves
Types of survivorship curves
Type I
Type II
Type III
The mortality rate is highest at a max age
Type I
In Type I curves…
Most individuals don’t die until they’re older
Parents invest lots of time raising their young
Examples of Type I curves
Elephants
Humans
Equal probability of dying at any age
Type II
Examples of Type II curve
Birds
Smaller mammals
most individuals die young
Type III
In Type III curves…
Organisms have hundreds of young at a time
Parents invest little time/energy in raising young
Examples of Type III curves
Fish
Insects
Invertebrates
Per capita rate of increase of population
Population growth
______ _____ is different between birth and death rates
Population growth
-r = ______
Decreasing
r = ______
Increasing
When the growth of a population is very rapid
Exponential growth
______ _____ cannot continue ______
Exponential growth; indefinitely
Exponential growth is represented by the ____ shaped curve
J
Logistic growth is represented by the ____ shaped curve
S
Logistic growth is because of _______ _______
Environmental resistance
The maximum number of individuals that a habitat can support indefinitely
Carrying capacity
Equation of exponential growth
G = rn
Equation of logistic growth
G = rn ( (k-n) / n)
What is G?
Population size of the following year
What is r?
Rate of increase per capita
What is n?
Number of individuals (females in exponential)
What is k?
Carrying capacity in logistic growth
What is rn?
Growth rate
Things that limit the population size due to an increase in the population
Density dependent factors
Density dependent factors
Food Water Shelter Sunlight Space Predation Infectious disease
Competition in population size limits
The more individuals, the less resources, the more competition
Types of competition
Interspecific competition
Intraspecific competition
Competition between different species
Interspecific competition
Competition within a species
Intraspecific competition
The factors that live that are unrelated to population density
Density independent factors
Density independent factors
Natural disasters
Industrial incidents
Reproductive strategies
R-selected species
K-selected species
R-selected species….
Live short lives Reproduce at an early age Offspring receive little care Offspring have low probability of surviving to reproductive age Density independent factors limit these
When conditions are favorable, r-selected species’ populations can ______
Explode
R-selected species are Type ____
III
K-selected species….
Live long lives Mature later in life Produce small number of offspring Offspring are given extended care Most live long enough to reproduce Density dependent factors limit these
K-selected species are Type ___ and Type ___
I and II
Examples of reproductive strategies
South American guppies
South American guppies…
Live in streams/rivers
Have 3 areas of predation intensities
Predation intensities of guppies
Cichlids
Rivulus
No predation
______ eat the adult guppies; ______ predation; ___-selected species
Cichlids; high; r
______ eat the young guppies; _____ predation; ___-selected species
Rivulus; moderate; r
No predation is a ___-selected species
K
With cichlids and rivulus, there are _____ babies being born
More
When there’s no predation, ____ babies are being born
Less
It was hypothesized that guppies from the first area would ______ faster and devote more energy to _____ due to ______ _____
Mature; reproduction; natural selection
They confirmed that there was a ______ _____ to their hypothesis
Genetic basis
They put guppies from Area ___ into Area ____ to see if they would turn from r to k, and they did
1; 3
The average population density of the whole world is ____ people per square kilometer
43
__/__ of the population is from India and China
1/3
Population growth rate = ___.___ % per year, but it is going _____
1.2%; down
Factors in the human population
Fertility
Mortality
Age structures
Birth rates shift from high to low
Demographic transition
First Stage of demographic transition
High birth and death rates
Population growth would be slow
Transitional Stage of demographic transition
Living conditions improve Learn how to control some diseases High birth rate Decreased death rate Typical of developing countries
Third Stage of demographic transition
Birth rate decreases
Death rate stays low/goes lower
Typical of more developed countries
Factors that affect birth rates
Economy
Social
Family planning
Government policies
Women with higher education tend to have _____ kids
Fewer
The more income a family makes, the _____ kids they’ll have
Fewer
Factors that affect death rates
Life expectancy
Improved public health
Improved medical technology
AIDS
Overall life expectancy = ___ years in developed countries, ___ years in less developed countries
75; 50
Population growth effects on the environment
Resources
Generate more waste
Pollution
Energy consumption
