Chapter 37 -Populations

Question 1

ecology

Answer 1

study of relationships among organisms and between organisms and the environment

Question 2

population

Answer 2

interbreeding members of the same species occupying the same region

Question 3

community

Answer 3

group of interacting populations that inhabit the same region

Question 4

ecosystem

Answer 4

a community and its nonliving environment including air, water, minerals, and fire

Question 5

habitat

Answer 5

physical place where an organism normally lives such as ocean, desert, and rain forest or even another organism

Question 6

population density

Answer 6

number of individuals of a species per unit area or volume of habitat

Question 7

population distribution

Answer 7

pattern describing where individuals are scattered throughout a habitat

Question 8

population dynamics

Answer 8

study of the factors that influence changes in a population’s size

Question 9

immigration

Answer 9

movement of individuals into a population

Question 10

emigration

Answer 10

movement of individuals out of a population

Question 11

birth rate

Answer 11

the number of new individuals produced per individual per unit time

Question 12

age structure

Answer 12

distribution of age classes in a population

Question 13

death rate

Answer 13

the number of deaths per individual per unit time

Question 14

life table

Answer 14

chart that shows the probability of surviving to any given age

Question 15

survivorship curve

Answer 15

graph of the proportion of individuals that survive to a particular age

Question 16

mark- recapture

Answer 16

a method commonly used in ecology to estimate an animal population’s size where it is impractical to count every individual

Question 17

catch by unit effort

Answer 17

formula to estimate population size and rate of decline, catching for the same amount of time but if the population go down then the CBUE would go down each year too

Question 18

Habitat heterogeneity

Answer 18

diversity or variety in habitat types

Question 19

Habitat homogeneity

Answer 19

a lot of habitat that is all the same. a lack of biodiversity

Question 20

More uniform spacing may occur (population distribution)

Answer 20

if individuals repel one another, as in the case of strongly territorial animals.

Question 21

Most often, however, a population’s distribution is somewhat

Answer 21

clumped, with individuals being attracted to one another or to the most favorable patches of habitat.

Question 22

Organisms may occur in a random pattern if

Answer 22

individuals neither strongly attract nor repel one another and the environment is relatively homogeneous (for example, on an exposed rock surface or in the deep shade under a dense forest canopy)

Question 23

what can habitat destruction do to populations.

Answer 23

eliminate some or all of a population

Question 24

limiting the further exchange of individuals and setting the stage for the evolution of a new species. How might this occur?

Answer 24

The isolated subpopulation often encounters a novel combination of selective forces, such as differences in sunlight, moisture, or nutrient availability. Previously rare variants may therefore have the greatest reproductive success in the new habitat. Over many generations, natural selection is likely to shape a genetically distinct subpopulation. If these genetic differences lead to new reproductive barriers, the subpopulation will be unable to interbreed with the parent population. The result: an entirely new species.

Question 25

The population size remains unchanged if

Answer 25

additions exactly balance subtractions

Births and deaths are the most obvious ways to add to and subtract from a population

Question 26

Humans have played an enormous role in the migration of other species.

Answer 26

Accidentally or intentionally, we have moved species all over the world. Often the newcomers settle harmlessly into their adopted home, but sometimes they disrupt the local ecosystem.

Question 27

What factors determine the birth rates and death rates in a population?

Answer 27

The birth rate is determined by the number of times an organism reproduces, how many offspring result from each reproductive episode, and the proportion of the population that is at reproductive age. The death rate is determined by nutrition, predation, accidents, and disease.

Question 28

What is the relationship between a life table and a survivorship curve?

Answer 28

The life table shows the probability of surviving at any given age. A survivorship curve is a graph generated from the life table.

Question 29

Describe the three patterns of survivorship curves.

Answer 29

Start revealed content.
In a Type I survivorship curve (“late loss”), most individuals survive to reproductive age and then die near the end of the maximum lifespan. In a Type II survivorship curve (“constant loss”), the death rate is constant throughout the lifespan. In a Type III survivorship curve (“early loss”), most deaths occur early in life, and few individuals survive to old age.

Question 30

per capita rate of increase (r)

Answer 30

difference between the birth rate and the death rate in a population

Question 31

exponential growth

Answer 31

population growth pattern in which the number of new individuals is proportional to the size of the population

Question 32

J-shaped curve

Answer 32

plot of exponential growth over time

Question 33

environmental resistance

Answer 33

combination of factors that limit population growth

Question 34

carrying capacity

Answer 34

maximum number of individuals that an ecosystem can support indefinitely; indicated by K

Question 35

logistic growth

Answer 35

population growth pattern in which the growth rate slows as the population’s size approaches the habitat’s carrying capacity

Question 36

S-shaped curve

Answer 36

plot of logistic growth over time

Question 37

density-dependent factor

Answer 37

population-limiting condition whose effects increase as a population’s density increases

Question 38

biotic

Answer 38

living

Question 39

density-independent factor

Answer 39

population-limiting condition that acts irrespective of population density

Question 40

abiotic

Answer 40

nonliving

Question 41

life history

Answer 41

the events of an organism’s life, especially those that are related to reproduction

Question 42

opportunistic (r-selected) life history

Answer 42

reproductive strategy characterized by short-lived, early-maturing individuals that have many offspring, with each receiving little parental investment

Question 43

equilibrium (K-selected) life history

Answer 43

reproductive strategy characterized by long-lived, late-maturing individuals that produce few offspring, with each receiving heavy parental investment

Question 44

Factors Affecting Population Growth: Additions - births

Answer 44

Number of reproductive episodes per lifetime
Number of offspring per reproductive episode
Age at first reproduction
Population age structure (proportion at reproductive age)

Question 45

Factors Affecting Population Growth: Additions - immigration

Answer 45

Number of reproductive episodes per lifetime
Number of offspring per reproductive episode
Age at first reproduction
Population age structure (proportion at reproductive age)

Question 46

Factors Affecting Population Growth: subtraction - deaths

Answer 46

availability of nutrients
predation
accidents
genetic/infectious disease

Question 47

Factors Affecting Population Growth: subtracion - emigration

Answer 47

availability of dispersal mechanism