Biology 100 Unit 23

Question 1

is a group of individuals of a single species that occupy the same general area.

Answer 1

population

Question 2

Individuals in a population
– __________________________________
– are influenced by the same __________________, – are likely to interact and breed with one another.

Answer 2

=rely on the same resources

-enviromental factors

Question 3

is the study of factors that affect a population

Answer 3

population ecology

Question 4

Populations can be influenced by the interactions

Answer 4

between biotic and abiotic factors, resulting in variations in population sizes.

Question 5

Population ecology is used to study
– How to develop _________________
– how to controll __________________
– ____________________

Answer 5

• sustainable fisheries
• pests and pathogens
• human population growth

Question 6

In Population ecology, factors that influence a population include:

Answer 6

• density
• structure
• size
• growth rate

Question 7

the number of individuals of a certain species in a given area.

Answer 7

population density

Question 8

To determine population density, it would be necessary to

Answer 8

census the entire population. (impractical or impossible)

Question 9

Instead, population densities are estimated by indirect indicators, such as number of ____________________ _______.

Answer 9

bird nests or radant burrows

Question 10

Another estimation technique is the ______________ __________________.

Answer 10

mark-recapture method

-Animals are trapped, marked, and then recaptured after a period of time.

Question 11

Patterns of Dispersion
 If individuals aggregate in patches, their dispersion is ___________. This is often due to nutrients distributed ___________.

Answer 11

clumped

unevenly

Question 12

Patterns of dispursion: In some cases, behavioral interactions between individuals ensures a nearly _______________.

Answer 12

equal spacing

Question 13

This type of dispersion pattern, equal spacing, is called _________.

Answer 13

uniform

Question 14

If there is no biotic or abiotic interaction to determine the dispersion, individuals may be _______________________.

Answer 14

spaced unpredictable

Question 15

During spaced or unpredictable spacing:
– This is the ______________ dispersion pattern.
– Commonly occurs in _________________.

Answer 15

random

rainforests

Question 16

– The age __________________ is the distribution of individuals among age groups.

Answer 16

structure of a population

Question 17

The age structure of a population provides insight into

Answer 17

the history of a populations survival repoductive success

-how the population relates to enviromental factors

Question 18

are graphic representations of life table data.

Answer 18

survivorship curves

Question 19

survivorship curves :

Type I, flat at start, reflect low death rates, and ______________ __________________

Answer 19

death rates increase in older groups

Question 20

survivorship curves:

Type II, mortality is __________________

Answer 20

constant over times

Question 21

survivorship curves :

Type III, high death rates at 1st, ________ __________________

Answer 21

few survive at an older age

Question 22

Two types of life history strategies are

Answer 22

opportunistic and equilibrial.

Question 23

Opportunists
– ________________________________________
– ________________________________________

Answer 23

• mature quickly and reproduce young

- produce manly offspring

Question 24

Opportunistic growing populations tend to follow the exponential growth model as indicated by a

Answer 24

type III survivorship curve.

Question 25

``` Equilibrists – _____________________________________ – _____________________________________ – produce fewer offspring than opportunists. – exhibit parental care. ```

Answer 25

- mature and reproduce later | - have a more elabrate context to their lives

Question 26

Populations following an equilibrial strategy exhibit a

Answer 26

type I survivorship curve.

Question 27

The exponential growth model describes the rate of expansion of a population under optimal growth conditions, with _________________________________.

Answer 27

no biotic and aniotic limitations

Question 28

growth model describes the rate of expansion of a population under optimal growth conditions,

Answer 28

the exponential growth model

Question 29

In nature, a population may grow exponentially for a while, but eventually

Answer 29

one or more environmental factors will limit its growth.

Question 30

The _________________ is therefore a more realistic model for wild populations.

Answer 30

logistic growth model

Question 31

It describes the growth of an idealized population that is slowed when it encounters limiting factors.

Answer 31

logistic growth model

Question 32

The________________ of an environment is the number of individuals that can be maintained by that environment.

Answer 32

carrying capacity

Question 33

This graph allows us to compare the two population growth models.

Answer 33

exponential growth map

Question 34

The addition of individuals to a population leads to competition of resources, this is referred to as ______________________________(competition of the same species)

Answer 34

intraspecific competition

Question 35

This means that population growth is largely__________ _________________, a biotic factor.

Answer 35

density dependent

Question 36

Density-dependent factors first slow

Answer 36

the population growth rate, then limit its size. – Their effects intensify as the population grows. – They result in an increase of a population’s death rate and a decrease in its birth rate.

Question 37

are unrelated to the number of individuals in the population.

Answer 37

Density-independent factors

Question 38

In nature, many populations never reach carrying capacity before some __________ _______________ _______________.

Answer 38

density independent factors limit their growth rate

Question 39

In a tight predator-prey relationship, as in the cycle of the snowshoe hare and the lynx, ____________________ _______________________.

Answer 39

both prey and predator cycle together

Question 40

Population ecology can help guide us toward resource management goals.

Answer 40

– Increase populations of organisms we wish to harvest – Decrease populations of pests – Save populations of organisms threatened with extinction

Question 41

The U.S. Endangered Species Act defines: | – An ___________________ as one that is in danger of extinction throughout all or a significant portion of its range

Answer 41

endangered species

Question 42

The U.S. Endangered Species Act defines: | – A ______________________ as one that is likely to become endangered in the foreseeable future

Answer 42

threatened species

Question 43

According to the logistic growth model, the fastest growth rate occurs when a population size is at roughly _______________________________.

Answer 43

1/2 of the carrying capacity

Question 44

Theoretically, populations should be harvested down to this level (1/2 carrying capacity) , assuming that ________________________________________________

Answer 44

growth rate and carrying capacity are stable over time.

Question 45

In the northern Atlantic cod fishery

Answer 45

– The fishery collapsed in 1992 and has not recovered – Estimates of cod stocks were too high – The practice of discarding young cod (not of legal size) at sea caused a higher mortality rate than was predicted

Question 46

Human Population Growth: |  The human population can be described using the ________________________________.

Answer 46

exponential growth

Question 47

To calculate the growth of the human population we use the same parameters as with other populations: ______ _________________________________________

Answer 47

birth rates and death rates

Question 48

_________________________: Birth rates were once higher than death rates, however both birth rates and death rates are near equilibrium showing no growth.

Answer 48

Demographic transition

Question 49

Another important parameter for describing the human population is

Answer 49

its age structure.

Question 50

An _______________________ shows the proportion of individuals in different age groups

Answer 50

age structure diagram

Question 51

Age structure diagrams show what percentage of people in a population is

Answer 51

young, of reproductive age, part of the work force, or retired.

Question 52

age structure diagrams It can help us predict

Answer 52

population growth in the immediate future and what to do about it.

Question 53

The wider the base of the age structure diagram, the faster the population growth because the next generation will soon enter their reproductive years. _______________________________

Answer 53

This is population momentum

Question 54

As the human population grows, ________________________ such as resource consumption and pollution, increase significantly.

Answer 54

density-dependent factors,

Question 55

Current Estimates • ___________ people within the next 20 years and • ___________ by mid-21st century.

Answer 55

8 billion | 9.5 billion

Question 56

Do we have sufficient resources to sustain 8 or 9 billion people?

Answer 56

To accommodate all the people expected to live on our planet by 2025, the world will have to nearly double food production.

Question 57

An __________________ is an estimate of the amount of land required to provide the raw materials an individual or a population consumes,

Answer 57

ecological footprint

Question 58

ecological footprint examples are:

Answer 58

- food - fuel - water - housing - waste disposal

Question 59

There is tremendous disparity in consumption throughout the world. – The world’s richest countries have 20% of the global population – Use ________ of the world’s resources – The rest of the world has 80% of the population – Uses just __________ of global resources

Answer 59

86% | 14%

Question 60

Some researchers estimate that – if everyone on Earth had the same standard of living as people living in the United States, – we would need the resources of ___________

Answer 60

4.5 earths