chapter 5

Question 1

id: a group of individuals belonging to the same species living together in a particular place at a particular time

Answer 1

Population

Question 2

why are populations studied in ecology?

Answer 2

1) because the individuals making them up use the same resources in a certain area;
2) affected by the same conditions in the area;
3) interact with other organisms in the same way
4) population studies hold the key to saving endangered species and controlling pest populations and disease epidemics

Question 3

id: (a characteristic of populations)
these are not present in the lower level of organization, individuals and may change from time to time

Answer 3

emergent properties

Question 4

enum: (6)
emergent properties

Answer 4

1) population size
2) population density
3) age distribution
4) natality rate
5) mortality rate
6) population growth rate

Question 5

enum: (4)
variables that affect population size

Answer 5

1) number of births
2) number of deaths
3) number of immigrants (joining the population)
4) number of emigrants (leaving the population)

Question 6

id: refers to the numbers of individuals of the same species occupying a unit of area at a particular time

Answer 6

population density

Question 7

Population density tends to be (lower, higher) in areas with plentiful resources than in areas with scarce resources.

Answer 7

higher

Question 8

which is more useful, population size or population density? why?

Answer 8

population density - because it relates the number of individuals and the wastes they produce with the amount of resources available in a unit of area

Question 9

id: the ability of a population to increase in size through reproduction whether by giving birth, budding or fission

Answer 9

natality

Question 10

id: refers to the greatest number of new individuals that can be produced under ideal environmental conditions

Answer 10

maximum natality

Question 11

id: refers to the number of new individuals produced under actual environmental conditions

Answer 11

realized natality

Question 12

id: refers to the number of deaths in a population

Answer 12

mortality

Question 13

id: it occurs when environmental conditions are ideal

Answer 13

minimum mortality

Question 14

id: environmental conditions cause organisms to die earlier than their physiological longevity would allow

Answer 14

realized mortality

Question 15

mortality varies with (health, age)

Answer 15

age

Question 16

id: the survivorship data of a group of individuals in a population that were born more or less together

Answer 16

a cohort

Question 17

how is a survivorship curve produced?

Answer 17

when the survivorship data of a group of individuals in a population that were born more or less together is plotted, with number surviving at the start of each age interval in the vertical axis and age on the horizontal axis

Question 18

enum: (3)
kinds of survivorship curves

Answer 18

Type I (convex curve)
- survivorship is high (mortality rate is low)
- individuals are young, MR increases as they grow older
(mammals with few offsprings that are large

Type II
- MR is more or less the same regardless of age
(some lizards, hydras, mice and rabbits)

Type III (concave curve)
- individuals of the population die a the free-swimming larval stage due to predation
- once the larvae have attached to a substratum and secrete the shell, more individuals survive (MR decreases)
- type of curve is shown by species that do not provide parental care to their offspring

Question 19

enum: (3)
age distribution pyramids

Answer 19

1) Expanding
- greater no. of young indivs
- expected to show rapid growth in the future
- undeveloped countries

2) Stable
- greater number of young indivs, but not much difference
- slow growth (40% of growth is due to immigration)
- developed countries

3) Collapsing
- greater number of older people than the young
- population size is declining (not enough replacement for the dead)

Question 20

ToF: Population size influences natality and mortality rates of a population and, thus, also affects population growth rate.

Answer 20

No, age distribution does

Question 21

A population with many young people entering the (reproductive, pre-reproductive) age is expected to increase in size in the future.

Answer 21

reproductive

Question 22

enum: (3)
division of age distribution

Answer 22

1) pre-reproductive stage
2) reproductive stage
3) post-reproductive stage

Question 23

ToF: The duration of these three stages varies with different organisms and with different cultures of peoples

Answer 23

true

Question 24

____________ have a long pre-reproductive stage during metamorphosis, followed by a brief reproductive period, after which they die. Similarly, the _______________ lays eggs only once in its lifetime and immediately dies soon after, its energy having been spent in swimming upstream from the ocean and in releasing its eggs

Answer 24

insects; pink salmon

Question 25

Population Growth Rate is Determined by an Organism's Innate ________ to ____________ and by __________ Factors that __________ Population Growth

Answer 25

Capacity; Reproduce; Environmental; Prevent

Question 26

how can number of births and deaths in a population be expressed?

Answer 26

as the average number of births and deaths per individual (per capita) during the time period

Question 27

id: the number of offspring produced per unit time by an average member of the population

Answer 27

per capita birth rate (b)

Question 28

id: per capita birth rate (by convention)

Answer 28

the number of births per 1000 individuals (by convention)

Question 29

id: the number of deaths per 1000 individuals

Answer 29

per capita death rate (d)

Question 30

id: the difference between the per capita birth rate and per capita death rate

Answer 30

per capita rate of increase

Question 31

_____________ is also the population growth rate, expressed on a per capita basis

Answer 31

Per capita rate of increase

Question 32

when the per capita rate of increase of a population is maximum (under favorable conditions, abundant resources and low population density, it is called _____________

Answer 32

biotic potential: intrinsic rate of increase (r) of the population

Question 33

enum: (5) factors influencing the intrinsic rate of increase (also called biotic potential) of a population - these factors are innate to the species

Answer 33

1) Age at first reproductive episode 2) Frequency of reproduction 3) Number of individuals produced at each reproductive episode 4) Length of reproductive period 5) Survival up to and through reproductive age

Question 34

The smaller the organism, the (lower, greater) is the per capita birth rate

Answer 34

greater (Elephants, for example, reproduce once every 4 years and have only 1 offspring. Dogs have puppies yearly with a litter of 4-6 and chickens lay eggs several times a year. Bacteria have the highest biotic potential. E. coli, for example, divides into two every 20 minutes)

Question 35

In the field where resources are limiting and conditions not always favorable due to disease and competition, e.g., the actual per capita rate of increase or realized r is (greater, lower) than rmax

Answer 35

lower

Question 36

what causes the difference between r and rmax?

Answer 36

environmental resistance, the sum total of the conditions and resources that prevent rmax from being realized

Question 37

id: the sum total of the conditions and resources that prevent rmax from being realized

Answer 37

environmental resistance

Question 38

When environmental conditions are favorable, resources unlimited and the population density is low, populations tend to __________

Answer 38

increase rapidly

Question 39

exponential growth produce a ____________ curve

Answer 39

j-shaped

Question 40

Exponential population growth is characterized by an accelerating population growth that occurs when optimal conditions allow a constant ____________ growth rate

Answer 40

per capita

Question 41

The unrestricted growth of populations in unlimited environments often lasts briefly only. It ends when the resources become ____________ to support the population, when an environmental condition _____________, like the coming of rain or snow, or when the ______________ season ends.

Answer 41

inadequate; changes; reproductive

Question 42

The lack of resources or environmental change that occurs would (decrease, increase) per capita death rate and (decrease, increase) per capita birth rate of a population, thus, affecting r.

Answer 42

increase; decrease

Question 43

what causes population to not increase exponentially indefinitely in nature? due to what?

Answer 43

the increase per capita death rate and decrease per capita birth rate of a population; lack of resources and environmental change

Question 44

what is a boom and bust pattern of population change?

Answer 44

when a population size declines, then increases again from year to year

Question 45

what kinds of plants and insects show a boom and bust population oscillation?

Answer 45

annual plants and insects

Question 46

Exponential population growth may be very important to populations during the process of ______________ themselves and during the process of __________ from some sort of exploitation - give an example

Answer 46

establishing; recovery; explosive algal growth in an enriched body of water and rapid increase of whale populations once whaling was stopped

Question 47

what happens when the number of organisms reached the population size that the resources in the environment can support for an indefinite period of time

Answer 47

population growth slows down

Question 48

what is the other term for the slowing down of population growth? how does its growth curve look like when graphed?

Answer 48

logistic population growth; sigmoidal (S-shaped growth curve)

Question 49

when the population approached the carrying capacity of the island, N/t becomes (smaller, bigger) and the line of the graph actually becomes __________ or (stable, fluctuates) near the carrying capacity

Answer 49

smaller; flat; fluctuates

Question 50

id: the population size when the population becomes stable

Answer 50

carrying capacity

Question 51

id: the population size that can be supported by the resources present in the environment growth is computed by taking into consideration K

Answer 51

carrying capacity

Question 52

id: the ratio N/K

Answer 52

environmental resistance

Question 53

environmental resistance (decreases, increases) as N increases

Answer 53

increases

Question 54

In logistic population growth, increase in population size is (slow, fast) at first (_________ phase), gradually becomes faster, then becomes rapid. As resources become (diminished, adequate) population increase slows down until ______________ is reached.

Answer 54

slow; lag; diminished; carrying capacity

Question 55

Theoretically, there is (no, more) further change in population size once N has reached K or the carrying capacity

Answer 55

no

Question 56

why do some species not make a smooth transition from exponential growth to logistic population growth?

Answer 56

because such populations use up their resources and temporarily overshoot or exceed the carrying capacity of their environment

Question 57

why do some species temporarily overshoot or exceed the carrying capacity of their environment?

Answer 57

because of a reproductive time lag

Question 58

what is a reproductive time lag?

Answer 58

the period needed for the birth rate to fall and the death rate to rise in response to resource overconsumption

Question 59

despite a reproductive time lag, population size still increase, why is this?

Answer 59

due to a population growth momentum

Question 60

Density-Dependent and Density-Independent Factors Limit Population Growth by Acting on __________________ and ___________________ rates

Answer 60

birth and death rates

Question 61

Some environmental factors may affect a bigger proportion of the population more when the population density is (low, high)

Answer 61

high

Question 62

enum: (3) factors that may affect population density

Answer 62

disease competition predation

Question 63

Competition becomes more intense when population density is (low, high), resulting in a (lowering, increasing) of population density. In like manner, an infection will affect a (lower, greater) number of individuals of the population when population density is high.

Answer 63

high; lowering; greater

Question 64

id: factors that regulate population size

Answer 64

density-dependent factors

Question 65

Density-dependent factors tend to regulate a population at a relatively constant size that is near the carrying capacity and this is a very good example of a _______________ system in nature

Answer 65

negative feedback system

Question 66

id: factors that affect population density whether population density is high or low

Answer 66

density-independent factors

Question 67

Density-independent factors are generally (biotic, abiotic)

Answer 67

abiotic

Question 68

id: factors that act separately or together, affecting the carrying capacity of an environment for a species

Answer 68

limiting factors

Question 69

The Human Population Continues to (Decrease, Increase) but World Per Capita Growth Rate has Declined over the Past Several Years

Answer 69

Increase

Question 70

After agriculture developed around 8000 BC, the human world population increased gradually for about (1,000 / 10,000) years before it reached 1 billion (around 1800). But after only (130, 150) years (in 1930), it reached 2 billion, and then 3 billion after (30, 130) years (in 1960) and 4 billion after 15 years (1975) In 2012, world population reached (7 billion, 10 billion), just as predicted by the United Nations World population has been, therefore, growing exponentially and if plotted, a (J, S) shaped curve is produced.

Answer 70

10,000; 130; 30; 7 billion; J-shaped

Question 71

id: a British clergyman and economist, was one of the first to recognize that the human population cannot continue increasing at a fast rate because it might outstrip the rate of food production. He pointed out that population growth could lead to famine, disease and war,

Answer 71

Thomas Malthus

Question 72

The world population is currently increasing by about ___ million people per year. This rate of increase of the world population was not due to an increase in birth rate, but due to a dramatic decrease in death rate.

Answer 72

83

Question 73

the world birth rate has (declined, inclined) since the early 1800s

Answer 73

declined

Question 74

Most published estimates place Earth's carrying capacity from _________ to ________ billion.

Answer 74

4 to 16 billion

Question 75

Earth's carrying capacity for humans is decided simply by natural environmental constraints.

Answer 75

no, also by peoples' choices

Question 76

enum: (3) Countries can be classified into two groups, highly developed and developing, based on their rates of ________

Answer 76

population growth degree of industrialization relative prosperity

Question 77

enum: (5) characteristics of highly developed countries

Answer 77

low population growth rates due to low birth rates low infant mortality rates longer life expectancies highly industrialized have higher average GNI PPP per capita

Question 78

id: the amount of time it would take for its population to double its size, assuming its current growth rate did not change

Answer 78

doubling time

Question 79

Doubling time identifies whether a country is highly, moderately or less developed. The shorter the doubling time of a country, the (less, more) developed the country.

Answer 79

less

Question 80

id: the number of children a couple must produce to "replace" themselves

Answer 80

replacement-level fertility

Question 81

The total fertility rate is _____ worldwide which is higher than replacement levels. It is _____ in highly developed countries, except the ______

Answer 81

2.6; 1.7; US

Question 82

id: the average number of children born to a woman in her lifetime

Answer 82

total fertility rate

Question 83

The Life Histories of Organisms may be __________, and Have a (Low, High) Intrinsic Rate of (Decrease, Increase) or Equilibrial, where the Populations of the Species are Near Carrying Capacity Much of the Time

Answer 83

opportunistic; high; increase

Question 84

id: the series of events from birth through reproduction and death, varies among species

Answer 84

life histories

Question 85

life history is the result of ________

Answer 85

natural selection

Question 86

Populations that exhibit a big-bang reproductive strategy, called semelparity, typically live in an unpredictable environment controlled by density- (dependent, independent) factors, such as climate.

Answer 86

independent

Question 87

id: populations that exhibit a big-bang reproductive strategy

Answer 87

semelparity

Question 88

Semelparous species are also called (r-selected, k-selected) species because they have a (low, high) intrinsic rate of increase or r.

Answer 88

r-selected species; high

Question 89

id: the type of life history shown by larger-bodied and longer- living species, they often mature late, produce few offspring several times in their lifetime and care for their young, a kind of reproductive strategy called iteroparity

Answer 89

equilibrial life history

Question 90

the population size of organisms with equilibrial life history is held near the carrying capacity by density- (dependent, independent) factors

Answer 90

density-dependent

Question 91

id: a reproductive strategy where species often mature late, produce few offspring several times in their lifetime and care for their young

Answer 91

iteroparity

Question 92

Iteroparous species are also called (r-selected, k-selected) species because they tend to do well, being (small, big) -bodied, in competition when their population size is near the carrying capacity

Answer 92

k-selected; big

Question 93

id: amount of energy, time and other resources allocated to the production and care of offspring

Answer 93

reproductive effort

Question 94

id: (2) before these vertebrates reach sexual maturity, they spend their energy and other resources for maintenance and growth. However, after they have become sexually mature, they have to allocate their limited energy into _______________ (3)

Answer 94

fish and reptiles growth, maintenance, and reproduction

Question 95

Organisms that delay reproduction will tend to grow (slower, faster) and reach a (smaller, larger) size, which is associated with a (lower, higher) reproductive rate. But delaying reproduction to a later age also (decreases, increases) the chance the individual will die before reproducing.

Answer 95

faster; larger; higher; increases

Question 96

where adult survival is higher, organisms delay reproduction and allocate (less, more) energy to reproduction

Answer 96

less

Question 97

In other words, during the course of evolution a ____________ between survival traits and traits that enhance reproduction have occurred, so as to increase the _______ of organisms

Answer 97

trade-off; fitness

Question 98

id: a population that is divided into several local populations in distinct habitat patches among which individuals occasionally migrate

Answer 98

metapopulation

Question 99

Population ecologists have discovered that many populations are not distributed as one large population across a landscape but as a ______________ or subpopulations in distinct habitat patches

Answer 99

series of local populations

Question 100

The patches of habitat vary in their ability to provide the _______________ of a species.

Answer 100

requirements

Question 101

id: areas where reproductive success is greater than local mortality and population densities are higher than those at less suitable sites.

Answer 101

good habitats; source habitats

Question 102

id: patches where local reproductive success is lower than local mortality

Answer 102

sink habitats

Question 103

a sink population will (decrease, increase) in size until extinction occurs

Answer 103

decrease

Question 104

ToF: Metapopulations are also created when humans alter the landscape, such as a forest, by fragmenting existing habitats of other organisms to make way for houses, cities, farms, etc.

Answer 104

True

Question 105

As a result, the concept of metapopulation has become an important area of study in conservation biology in relation particularly to ___________ and _____________ species.

Answer 105

endangered and threatened

Question 106

id: exist between two or more populations that allow individuals from source habitats to reach sink habitats to increase population size and improve the genetic diversity of populations in sink habitats

Answer 106

Habitat corridors

Question 107

Habitat corridors made by man (can, cant) help the animals

Answer 107

can

Question 108

enum: (3) Factors that allow Populations to be Distributed Uniformly, Randomly or Clumped Together in Space

Answer 108

Physical Conditions Chemical Conditions Biological Factors

Question 109

ToF: some organisms can tolerate the full range of conditions existing on earth

Answer 109

false

Question 110

enum: (3) types of spatial distribution of plants a

Answer 110

clumped random uniform

Question 111

enum: (4) resources influencing the spatial distribution of plants and animals

Answer 111

water light mates underground nutrients

Question 112

ToF: in some cases, population distribution may vary as the plants age

Answer 112

true

Question 113

enum: (3) what influences the Commonness and Rarity of Species

Answer 113

Local Population Size Geographic Range Habitat Tolerance

Question 114

why is it that some populations tend to be more vulnerable to extinction than others?

Answer 114

abundance of the species - rare species are in greater danger of extinction while abundant ones are not

Question 115

who devised a classification system to determine the commonness or rarity of species based on a combination of three factors?

Answer 115

Deborah Rabinowitz

Question 116

organisms which have a large population size, extensive range of distribution and broad range of tolerance for conditions are the most (rare, common) organisms

Answer 116

common

Question 117

organisms with small population size, (narrow, broaden) geographical range and low tolerance for environmental conditions show extreme rarity and are, therefore, very prone to extinction

Answer 117

narrow

Question 118

ToF: If a species suffers in only one aspect, such as small local populations but has extensive range and broad tolerance for habitat, its chances for extinction is still less

Answer 118

false: Even if a species suffers in only one aspect, such as small local populations but has extensive range and broad tolerance for habitat, its chances for extinction is also great.

Question 119

Ecologists have discovered that (there is, there is no) strong positive correlation between size of geographic range and population size

Answer 119

there is

Question 120

Species that have large local populations have (narrow, extensive) geographic range, while species with small local populations generally have a (narrow, extensive) range of distribution also

Answer 120

extensive; narrow