2Chapter 4 Population Ecology Section 1: Population DynamicsSection 2: Human Population
3The number of organisms per unit area Chapter 4Population Ecology4.1 Population DynamicsPopulation DensityThe number of organisms per unit areaSpatial DistributionDispersion is the pattern of spacing of a population.Visualizing Population Characteristics
4Chapter 4Population Ecology4.1 Population DynamicsPopulation RangesA species might not be able to expand its population range because it cannot survive the abiotic conditions found in the expanded region.Common dolphinPupfish
5Population-Limiting Factors Chapter 4Population Ecology4.1 Population DynamicsPopulation-Limiting FactorsThere are two categories of limiting factors—density-independent factors and density-dependent factors.
6Density-Independent Factors Chapter 4Population Ecology4.1 Population DynamicsDensity-Independent FactorsAny factor in the environment that does not depend on the number of members in a population per unit area is a density-independent factor.Weather eventsFireHuman alterations of the landscapeAir, land, and water pollution
7Density-Dependent Factors Chapter 4Population Ecology4.1 Population DynamicsDensity-Dependent FactorsAny factor in the environment that depends on the number of members in a population per unit area is a density-dependent factor.Biotic factorsDiseasePopulation BiologyCompetitionParasites
8Population Growth Rate Chapter 4Population Ecology4.1 Population DynamicsPopulation Growth RateThe population growth rate (PGR) explains how fast a given population grows.The natality of a population is the birthrate in a given time period.
9Exponential Growth Model Chapter 4Population Ecology4.1 Population DynamicsExponential Growth ModelExponential growth occurs when the growth rate is proportional to the size of the population.All populations grow exponentially untilsome limiting factor slows the population’sgrowth.
10Chapter 4Population Ecology4.1 Population DynamicsLogistic Growth ModelThe population’s growth slows or stops following exponential growth, at the population’s carrying capacity.
11Chapter 4Population Ecology4.1 Population DynamicsA population stops increasing when the number of births is less than the number of deaths or when emigration exceeds immigration.
13Chapter 4Population Ecology4.1 Population DynamicsCarrying CapacityThe maximum number of individuals in a species that an environment can support for the long term is the carrying capacity.Carrying capacity is limited by the energy, water, oxygen, and nutrients available.
14Reproductive Patterns Chapter 4Population Ecology4.1 Population DynamicsReproductive PatternsSpecies of organisms vary in the number of births per reproduction cycle, in the age that reproduction begins, and in the life span of the organism.
15An r-strategist is generally a small organism. Chapter 4Population Ecology4.1 Population DynamicsThe rate strategy, or r-strategy, is an adaptation for living in an environment where fluctuation in biotic or abiotic factors occur.An r-strategist is generally a small organism.Short life spanProduces many offspring
16A k-strategist is generally a larger organism. Chapter 4Population Ecology4.1 Population DynamicsThe carrying-capacity strategy, or k-strategy, is an adaptation for living in stable environments.A k-strategist is generally a larger organism.Long life spanProduces few offspring
174.2 Human Population Human Population Growth Chapter 4Population Ecology4.2 Human PopulationHuman Population GrowthThe study of human population size, density, distribution, movement, and birth and death rates is demography.
18Technological Advances Chapter 4Population Ecology4.2 Human PopulationTechnological AdvancesFor thousands of years, environmental conditions kept the size of the human population at a relatively constant number below the environment’s carrying capacity.Humans have learned to alter the environment in ways that appear to have changed its carrying capacity.
19Human Population Growth Rate Chapter 4Population Ecology4.2 Human PopulationHuman Population Growth RateAlthough the human population is still growing, the rate of its growth has slowed.
20Trends in Human Population Growth Chapter 4Population Ecology4.2 Human PopulationTrends in Human Population GrowthPopulation trends can be altered by events such as disease and war.Human populationgrowth is not the same in all countries.
22Zero Population Growth Chapter 4Population Ecology4.2 Human PopulationZero Population GrowthZero population growth (ZPG) occurs when the birthrate equals the death rate.The age structure eventually should be more balanced with numbers at pre-reproductive, reproductive, and post-reproductive ages being approximately equal.
23pre-reproductive stage, reproductive stage, and post- Chapter 4Population Ecology4.2 Human PopulationAge StructureA population’s age structure is the number of males and females in each of three age groups:pre-reproductive stage, reproductive stage, and post-reproductive stage.
24Human Carrying Capacity Chapter 4Population Ecology4.2 Human PopulationHuman Carrying CapacityScientists are concerned about the human population reaching or exceeding the carrying capacity.An important factor is the amount of resources from the biosphere that are used by each person.
25Chapter Resource Menu Chapter Diagnostic Questions Population EcologyChapter Resource MenuChapter Diagnostic QuestionsFormative Test QuestionsChapter Assessment QuestionsStandardized Test Practicebiologygmh.comGlencoe Biology TransparenciesImage BankVocabularyAnimationClick on a hyperlink to view the corresponding lesson.
26What term is used to describe the number of Chapter 4Population EcologyChapter Diagnostic QuestionsWhat term is used to describe the number ofindividuals moving into a population?emigrationimitationimmigrationmigration
27What is population density? Chapter 4Population EcologyChapter Diagnostic QuestionsWhat is population density?pattern of spacing of a population inan areanumber of organisms in an areacharacteristics of a populationmanner in which a population grows
28When does zero population growth occur? Chapter 4Population EcologyChapter Diagnostic QuestionsWhen does zero population growth occur?when birth rate equals death ratewhen death rate exceeds birth ratewhen birth rate exceeds death ratewhen there are zero births
29Which is a density-dependent factor? Chapter 4Population Ecology4.1 Formative QuestionsWhich is a density-dependent factor?diseasefirefloodingweather
30Which is a density-independent factor? Chapter 4Population Ecology4.1 Formative QuestionsWhich is a density-independent factor?competitionextreme coldparasitespredation
31Which factor can limit the carrying capacity of a population? Chapter 4Population Ecology4.1 Formative QuestionsWhich factor can limit the carrying capacityof a population?emigrationpredationavailable nutrientsextreme temperatures
32The study of the size, density, distribution, Chapter 4Population Ecology4.2 Formative QuestionsThe study of the size, density, distribution,and movement of the human populationis _______.bioinformaticsdemographyecologyethnography
33Which is a primary reason for the decline in the Chapter 4Population Ecology4.2 Formative QuestionsWhich is a primary reason for the decline in thepercent growth of the human population after 1962?decreased agriculturefamine and warssetbacks in medicinevoluntary populationcontrol
34What will happen to the human population Chapter 4Population Ecology4.2 Formative QuestionsWhat will happen to the human populationwhen the birthrate equals the death rate?CDCHPGPGRZPG
35Which type of population growth model does this graph represent? Chapter 4Population EcologyChapter Assessment QuestionsWhich type of population growth model doesthis graph represent?exponentialspatialgeneticlogistic
36Based on the information in the graph, infer which Chapter 4Population EcologyChapter Assessment QuestionsBased on theinformation in thegraph, infer whichstatement accuratelyrepresents theinformation provided.
37India has very little land for farming. Chapter 4Population EcologyChapter Assessment QuestionsIndia has very little land for farming.Germany is smaller per acre than theUnited States.More land is used to support an individualin the United States.A person in Indonesia requires more landthan a person in Brazil.
38Use the graph to explain the growth of the mice population. Chapter 4Population EcologyChapter Assessment QuestionsUse the graph to explain the growth of themice population.
39Answer: If two adult mice breed and produce a litter Chapter 4Population EcologyChapter Assessment QuestionsAnswer: If two adult mice breed and produce a litterand their offspring survive to breed, then thepopulation grows slowly at first. This slowgrowth is defined as the lag phase. The rateof population growth begins to increaserapidly because the total number oforganisms that are able to reproduce hasincreased. Exponential growth occurs whenthe growth rate is proportional to the size ofthe population. All populations growexponentially until some limiting factor slowsthe population’s growth.
40An ecologist estimates a population density of Chapter 4Population EcologyStandardized Test PracticeAn ecologist estimates a population density of2.3 lemmings per square meter of tundra. Whatwould be the approximate number of lemmingsover 1000 square meters of tundra?0.23232302300
41The ecologist finds that over a 1000m2 plot of Chapter 4Population EcologyStandardized Test PracticeThe ecologist finds that over a 1000m2 plot oftundra, lemmings tend to concentrate in clumpsin drier areas. What is the term for this patternof spacing?densitydispersionlogistic spacingspatial distribution
42Brine shrimp are able to survive only in certain Chapter 4Population EcologyStandardized Test PracticeBrine shrimp are able to survive only in certainlakes that have a very high salt concentration.Which is the correct population characteristic ofbrine shrimp?It is density-dependent.It is limited by biotic factors.It has a limited spatial distribution.It is randomly dispersed in the environment.
43Why does the population growth level off at 10,000? Chapter 4Population EcologyStandardized Test PracticeWhy does the population growth level offat 10,000?
44Biotic factors have made survival difficult. Chapter 4Population EcologyStandardized Test PracticeBiotic factors have made survival difficult.The population has reached its carryingcapacity.Density-independent factors have slowedthe growth of the population.Immigration into the population hasreached the maximum limit.
45Which organism is the best example of a k-strategist? Chapter 4Population EcologyStandardized Test PracticeWhich organism is the best example of ak-strategist?wolfgrasshopperrabbitwhale