Populations (Chapter 37) Exam prep
Ecological scales - correct answers- populations,
- community
- ecosystem
- biosphere
Ø A POPULATION consists of..... - correct answersinterbreeding organisms of one species occupying the
same area at the same time
Ø A COMMUNITY includes all.... - correct answerspopulations, representing multiples species, in the
same region
Ø An ECOSYSTEM is the.... - correct answersbiotic, or living, community plus the ABIOTIC, or nonliving,
environment
Ø Finally BIOSPHERE is... - correct answersall parts of the planet where life exists
More on populations...
(Habitat)
(Population density) - correct answersØ A HABITAT is the physical location where the members of a
population live
Ø These saguaro cacti grow only in the hot arid deserts of the southwestern US
Ø POPULATION DENSITY is the number of individuals of a species per unit area or unit volume of a
habitat
Population distributions: - correct answersdescribes how individuals are scattered through the habitat
Ø Uniform
Ø Clumped
Ø Random
uniform population distribution - correct answersindividuals are evenly spaced throughout an area,
happens when individuals hold a territory or compete for space
- These penguins live in dense, uniformity spaced populations
clumped population distribution - correct answersLiving in large groups
-enhances feeding opportunities and protection form predators
ex: schools of fish
random population distribution - correct answers-no pattern
*trees*
, Estimating population size. Consider this population of wildebeest. How can the number of individuals
be determined? - correct answersØ Aerial photos
Ø Sampling small subset
Ø Mark-recapture
Subpopulations - correct answerswhen a large population is broken up into smaller groups that live in
isolated patches
- Many circumstances may separate a population, such as formation of a mountain range or a body of
water. The separated populations are local subpopulations. If separated for a long period of time,
subpopulations may become new species.
What is population density? - correct answersthe number of individuals per unit area or volume
Birth and deaths affect population size
- If an ecologist wants to estimate how a chipmunk population will change over time, what factors
should be taken into consideration when determine population growth rate? - correct answers- birth
rate
- immigration
- death rate
- emigration
Factors that increase population size
(birth rate)
(immigration) - correct answers- Births and migration into the population increase population size
- BIRTH RATE is the number of individuals produced per unit of time
- IMMIGRATION is the movement of individuals into a population
Factors that decrease population size
(death rate)
(emigration) - correct answers- Deaths and migrations out of the population decrease the population
size
- DEATH RATE is the number of deaths per unit of time
- EMIGRATION is the movement of individuals out of a population
Age structure - correct answers- A population's AGE STRUCTURE or distribution age classes, helps
determine whether a population is growing, stable, or declining
Examples of two different age structures - correct answers- The white oak population has mostly young
individuals, indicating a high potential for future growth. Dying trees are replaced with many young
trees
- The cottonwood population has few young individuals, indicating that reproductive success is low. The
population size will decline as dying trees aren't replaced with young trees
Ecological scales - correct answers- populations,
- community
- ecosystem
- biosphere
Ø A POPULATION consists of..... - correct answersinterbreeding organisms of one species occupying the
same area at the same time
Ø A COMMUNITY includes all.... - correct answerspopulations, representing multiples species, in the
same region
Ø An ECOSYSTEM is the.... - correct answersbiotic, or living, community plus the ABIOTIC, or nonliving,
environment
Ø Finally BIOSPHERE is... - correct answersall parts of the planet where life exists
More on populations...
(Habitat)
(Population density) - correct answersØ A HABITAT is the physical location where the members of a
population live
Ø These saguaro cacti grow only in the hot arid deserts of the southwestern US
Ø POPULATION DENSITY is the number of individuals of a species per unit area or unit volume of a
habitat
Population distributions: - correct answersdescribes how individuals are scattered through the habitat
Ø Uniform
Ø Clumped
Ø Random
uniform population distribution - correct answersindividuals are evenly spaced throughout an area,
happens when individuals hold a territory or compete for space
- These penguins live in dense, uniformity spaced populations
clumped population distribution - correct answersLiving in large groups
-enhances feeding opportunities and protection form predators
ex: schools of fish
random population distribution - correct answers-no pattern
*trees*
, Estimating population size. Consider this population of wildebeest. How can the number of individuals
be determined? - correct answersØ Aerial photos
Ø Sampling small subset
Ø Mark-recapture
Subpopulations - correct answerswhen a large population is broken up into smaller groups that live in
isolated patches
- Many circumstances may separate a population, such as formation of a mountain range or a body of
water. The separated populations are local subpopulations. If separated for a long period of time,
subpopulations may become new species.
What is population density? - correct answersthe number of individuals per unit area or volume
Birth and deaths affect population size
- If an ecologist wants to estimate how a chipmunk population will change over time, what factors
should be taken into consideration when determine population growth rate? - correct answers- birth
rate
- immigration
- death rate
- emigration
Factors that increase population size
(birth rate)
(immigration) - correct answers- Births and migration into the population increase population size
- BIRTH RATE is the number of individuals produced per unit of time
- IMMIGRATION is the movement of individuals into a population
Factors that decrease population size
(death rate)
(emigration) - correct answers- Deaths and migrations out of the population decrease the population
size
- DEATH RATE is the number of deaths per unit of time
- EMIGRATION is the movement of individuals out of a population
Age structure - correct answers- A population's AGE STRUCTURE or distribution age classes, helps
determine whether a population is growing, stable, or declining
Examples of two different age structures - correct answers- The white oak population has mostly young
individuals, indicating a high potential for future growth. Dying trees are replaced with many young
trees
- The cottonwood population has few young individuals, indicating that reproductive success is low. The
population size will decline as dying trees aren't replaced with young trees
