Chapter 23 Flashcards

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1
Q

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

A

Population

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2
Q

Individuals in a population (3)

A
  • rely on the same resources
  • are influenced by the same environmental
  • are likely to interact and breed with one another
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3
Q

_____________ is the study of factors that affect a population

A

Population ecology

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4
Q

Populations can be influenced by the interactions between _______________, resulting in variations in population size.

A

Biotic and abiotic factors

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5
Q

Population ecology is used to study(3)

A
  • How to develop sustainable fisheries
  • how to control pest and pathogen
  • human population growth
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6
Q

In population ecology, factors that influence a population include: (4)

A
  • density
  • structures
  • size
  • growth rate
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7
Q

__________: the number of individuals of a certain species in a given area

A

Population density

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8
Q

To determine population density, it would be necessary to census the ____________.

A

entire population

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9
Q

population densities are estimated by indirect indicators, such as number of _________________.

A

birds nest or rodent burrows

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10
Q

Another estimation technique is the _______________.

A

mark-recapture method

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11
Q

Mark-recapture method

A

animals are trapped, marked and then recaptured after a period of time

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12
Q

If individuals aggregate in patches, their dispersion is ______. This is often due to nutrients distributed _____.

A

Clumped

unevenly

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13
Q

In some cases, behavioral interactions between individuals ensures a nearly _________.

A

equal spacing

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14
Q

equal spacing this type of dispersion pattern is called __________.

A

uniform

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15
Q

This is the ________ dispersion pattern

A

random

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16
Q

If there is no biotic or abiotic interaction to determine the dispersion, individuals may be spaced unpredictably, this is the random dispersion pattern, commonly occurs in _______

A

rainforest

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17
Q

The age ______________ is the distribution of individuals among age groups

A

structure of a population

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18
Q

The age structure of a populations provides insight into: (3)

A

the history of a populations survival

  • reproductive success
  • how the population relates to environmental factor
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19
Q

Type I,

A

Flat at start, reflect low death rates, and death rates increase in older groups

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20
Q

Type II

A

mortality is constant over time

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21
Q

Type III

A

high death rates at 1st, and few survive to older age

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22
Q

Two types of life history strategies are _________ and_________.

A

opportunistic

equilibrial

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23
Q

Opportunistic (2)

A
  • mature quickly and reproduce young

- produce many offspring

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24
Q

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

A

Type III survivorship curve

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25
Q

Equilibrists(4)

A
  • Mature and reproduce older
  • have a more elaborate social context to their lives
  • produce fewer offsprings than opportunists
  • exhibit parental care
26
Q

Populations following an equilibrial strategy exhibit a _______________________.

A

type I survivorship curve

27
Q

The ____________ describes the rate of expansion of a population of a population under optimal growth condtions, with no biotic or abiotic limitation

A

Exponential growth model

28
Q

In nature, a population may grow exponentially for a while, but eventually one or more environmental factors will limit its _________.

A

growth

29
Q

The _____________ is therefore a more realistic model for wild populations

A

logistic growth model

30
Q

The logistic growth model describes

A

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

31
Q

The _________ of an environment is the number of individuals that can be maintained by that environment

A

carrying capacity

32
Q

What factors contribute to the slowing of the growth rate in the logistic growth curve?

A

Intraspeific competition

density-dependent

33
Q

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

A

Intraspecific competition

34
Q

This means the population growth is largely __________, a biotic factor

A

density-dependent

35
Q

___________ first slow the population growth rate, then limit its size.

A

Density-dependent factor

36
Q

Density-dependent factor(2)

A
  • Their effects intensify as the population grows

- They result in a increase of a population’s death rate and a decrease in its birth rate

37
Q

__________ are unrelated to the number of individuals in the population.

A

Density-independent factor

38
Q

Density-independent factor include

A

Abiotic event

39
Q

in nature, many populations never reach carrying capacity before some_____________?

A

density-independent factors limit their growth rate

40
Q

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

A

both prey and predator cycle together

41
Q

Population ecology can help guide us toward resource management goals for example (3)

A
  • Increase populations of organisms we wish to harvest
  • Decrease populations of pests
  • Save populations of organisms threatened with extinction
42
Q

The U.S. endangered species act defines(2)

A
  • endangered species

- Threatened species

43
Q

An __________ as one that is in danger of extinction throughout all or a significant portion of its range

A

Endangered species

44
Q

A _____________ as one that is likely to become endangered in the foreseeable future

A

Threatened species

45
Q

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

A

Half the carrying capacity

46
Q

Theoretically, populations should be harvested down to this level, assuming that growth rate and carrying capacity are stable over time

A

half the carrying capacity

47
Q

In northern Atlantic cod fishery

A
  • estimates of cod stocks were to high
  • the practice of discarding young cod(not of legal size) at sea caused a high mortality rate than was predicted
  • the fishery collapsed in 1992 and had not recovered.
48
Q

The human population can be described using the ___________________.

A

exponential growth model

49
Q

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

A

Birth rates and death rates

50
Q

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

A

Demographic transition

51
Q

Another important parameter fro describing the human population is its __________.

A

age structure

52
Q

An ____________ shows the proportion of individuals in different age group.

A

age structure diagram

53
Q

show what percentage of people in a population is young, of reproductive age, part of the work force, or retired.

A

age structure diagram

54
Q

it can help us predict population growth in the immediate future and what to do about it,

A

age structure diagram

55
Q

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

A

population momentum

56
Q

As the human population grows, density-dependent factors, such as resource ________ and _______, increase significantly

A

Consumption and pollution

57
Q

Current estimates

  • ______people within the next 20 years and
  • _______ by mid-21st century
A

8 billion

9.5 billion

58
Q

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

A

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

59
Q

An ecological footprint is an estimate of the amount of land required to provide the raw materials an individual or a population consumes, including (5)

A
  • food
  • fuel
  • water
  • housing
  • waste disposal
60
Q

-the worlds richest countries have 20% of the global population

A

use 86% of the worlds resources

61
Q

The rest of the world has 80% of the population

A

uses just 14% of global resources

62
Q

some researches estimate that if everyone on earth had the same standard of living as people living in the united states,

A

we would need the resources of 4.5 planted earth