Populations and Communities Flashcards
(119 cards)
1
Q
define recessive allele
A
the allele tat has no noticeable effect on the organism’s appearance when 2 different alleles are inherited from the parentsd
2
Q
whats a parasite
A
an organism that lives on or in a host organism from or at the expense of its host
3
Q
define population crash
A
when a population decreases very rapdily
4
Q
whren is uniform distribution typically nseen
A
in artificial populations and birds of prey or other organisms that behave territorially to defend their resources and protect their young
5
Q
define ecosystem
A
the interaction beetween living organisms and their environment
6
Q
what factors influence distribution patterns (2)
A
the distribution of resources in a habitat and the interactions among community members
7
Q
define environmental resistance
A
the combined effects of various interacting limiting factors on the growth of a population
8
Q
what does exponential growth phase cause
A
the population to grow rapidly
9
Q
assuming nothing is limiting the growth of either population, how will the amount of increase in a large population compare to that in a small population and why
A
the amount of increase in a large population will be greater because there are more individuals that can reproduce
10
Q
true or false: secondary nsuccession and primary succession have different process
A
false; the processes are similary other then nutrient rich soil already being present in secondary succession
11
Q
true or false: hosts are only involved in parasitism
A
false; they can be involved in all 3 types of symbiotic relationships
12
Q
who do primary consumers have a direct relationship with
A
their predators/secondary consumers
13
Q
define ecological niche
A
all the biotic and abiotic fators that are required for the organism to survive as well as the organism’s interactions with other species
14
Q
define intraspecific competition
A
the competition for limited resources among members of the same species
15
Q
define immigration
A
the movement of individuals into a population
16
Q
what are the three forms of symbiosis
A
mutualism, commensalism and parasitism
17
Q
define ecology
A
the study of relationships between living organisms and their environment
18
Q
define mutualism
A
when both partners in a symbiotic relationship benefit from the relationship or depend on it to survive
19
Q
what can per capita growth be used for
A
to compare populations of the same species that are different sizes or live in different habitats
20
Q
define k selected strategies
A
a life strategy designed to take advantage of stable environmental conditions
21
Q
define mutation
A
permanent changes in the genetic material of an organism
22
Q
define predators
A
organisms that kill and consume other organisms
23
Q
true or false: k selected strategies live close to the carrying capacity of their habitat
A
true
24
Q
whats the theory of evolution by natural selection
A
that new variants of species continually arise in populations but some variants thrive and others die off because they cant survive in their environment; the variants that thrive produce more offspring which slowly changes the population towards the favorable traits over time
25
derfine r selected strategies
a life strategy designed to take advantage of favourable conditions
26
define allele
alternate forms of the same gene
27
whats symbiosis
the direct or close relationship between individuals of different species that live together
28
define logistic growth pattern
type of population increase where growth is slow at first, steepens in an exponential pattern and then levels off due to environment resistance such as competition
29
what does random distriution cause
individuals or pairs of organisms to be distributed thorughout a suitable habitat with no identifiable pattern
30
define population genetics
the study of genetic diversity in populations
31
define heterozygous
when there are 2 different alleles at a locus
32
define exponential growth
growth of a population in which the increase occurs in a repeated douvling pattern
33
why are parasites an important factor in limiting the growth of host populations
when an individual succumbs to parasites it reduces the density of the population which reduces competition for limited resources; weakened hosts may also become prey for other animals
34
what is biotic potential determined by (5)
- the number of offspring per reproductive cycle
- the number of offspring that survive long enough to reproduce
- the age of reproductive maturity
- the number of times an individual can reproduce in a lifespan
- the lifespan of the individual
35
define per capita growth
the change in population size per individual over a given time frame
36
define emigration
the movement of individuals out of a population
37
when does density dependent factors not impact growth
when the population is small and well below the carrying capacity of the habitat
38
what are population dynamics driven by
the interactions among individuals within the same population or from different populations
39
define genotype
genetic makeup of an individual that remains constant throughout its life
40
what is growth rate used for
to measure increases or decreases in a population size
41
what are the general events in a boom or bust cycles/predator-prey population cycles (7)
1. the larger a prey population is, the more food that is available to its predators
2. gives the predators more energy to reproduce and care for their young
3. allows the predator population to increase
4. with a greater number of predators the prey population will decline
5. causes a more intense competition among the predators for food which becomes a limiting factor
6. the predator population declines
7. with fewer predators the prey population increases
42
whats population dynamics
the changes that occur in populations over time
43
what does carrying capacity represent
the number of idnividuals 8in a popualtion that can live in a given enviornment without depleting the resources they need or harming their habitat or themselves
44
define exponential growht pattern, and what shape it shows
pattern exhibited by a population which is increasing exponentially, resulting in a j shaped curve showing a brief lag phase followed by a steep increase in the growth curve
45
true or false: intraspecific competition is a density-dependent factor that limits the growth of a population
true
46
what are some characteristics of k selected species (4)
- few offspring per reproductive cycle
- one or both parents care for the offspring when its young
- the offspring take a relatively long time to mature and reach reproductive age
- have a relatively long lifespan
- tend to have larger bodies compared to organisms that have r-selected strategies
47
what is succession driven by
both abiotic and biotic factors
48
what are some characteristics of producer-consumer interactions (4)
- scarcity of a producer series is a factor that can limit a consumer species population
- a dense population of consumers may control the growth of a producer population
- one of the factors in the boom or bust cycles observed in some population
- influence natural selection for adaptive traits
49
define species
structurally similar organisms that can mate and produce fertile offspring in nature
50
define locus
location of a gene on a chromosome
51
define lag phase
when the growth of a population is slow at the beginning because there are only a few individuals to reproduce
52
define interspecific competition
competition between two or more populations for limited resources
53
what two factors ad to a population size
birth and immigration
54
define dominant allele
the allele that is expressed in the individuals appearance when 2 different alleles are inherited from the parents
55
define parasitism
a form of symbiosis in which one partner (the parasite) benefits at the expense of its host
56
what does environmental resistance prevent
a population from growing at its biotic potential
57
define density dependant facotr
biotic factor that limits a havits carrying capacity
58
define climax community
the last or final stage of succession in an area
59
what is the general chronological order of events in primary succession (9)
1. an area that is bare with no soil present is colonized by organisms that tend to be small and opportunistic and are able to grow in harsh conditions
2. as some of the organisms start to die, soil begins to form
3. as soil builds up, its nutrient content, moisture content and pH change which allows larger species such as mosses to grow
4. species such as grasses, annual herbs shrubs and trees follow
5. the plants compete for light and living space
6. some populations survive and replace other populations that die due to interspecific competition and changing habitat
7. animals may come and join the community
8. species of plants and animals change
9. a climax community is formed and will remain stable unless there is a major ecological disturbance
60
whats pro9tective colouration
body colour as a natural defence mechanism
61
whats an ecological community
an association of interaction populations that inhibit a defined area
62
what is one of the main contributers to why no two species can share the exact same ecological niche
interspecific competition
63
what are some causes of environmental resistance (5)
- decreasing oxygen supply
- low food supply
- disease
- predators
- limited space
64
define primary seuccesion
the development of a new community in a previously barren are where there is no soil present
65
when does the impact of a density dependant factor increase
when the density of a population incrteases
66
what does growth rate not takre into account
initial population size
67
define variation
the difference between individuals of the same species
68
define secondary consumer
organism that eats primary consumers
69
define sucession
the sequence of invasion adn replacement of species in an ecosystem over time
70
when does ranodm distribution occur
when resources are very abundant and population members do not have to compete with one another or group together for survival
71
define environment
an organism's surroundings
72
define biotic potential
the highest possible per capita growth rate for a population
73
define age pyramid
tool that demographers use to help them assess a populations potential for growth
74
define biotic factors
living things within an ecosystem
75
what does an inverted triangle shaped age pyramid indicate
that the population is declining
76
who do primary producers have a direct relationship with
the primary consumers who eat them
77
whats genetic variation
differences in genetics within a populaiton that is cased by random mutation and natural selection
78
define abiotic factors
non-living components of an ecosystem
79
what are the typical colours that predators associate with dangerous or unpalatable animals
black, yellow and red
80
define adaptation
the act of changing something or changing behavior to adjust to new environments or changes in a current environment
81
whats a host
an organism that harbours another organism, providing it with nourishment and shelter
82
what are 3 factors that affect population growth
- various biotic and abiotic factors
- biotic limiting factors regarding how fast and how often a species is able to reproduce
- the ability of a habitat to support a population
83
define ecological disturbance
an event that changes the structue of a community and sometimes destroys all actively growing organisms
84
define habitati
the natural home or environment of an animal, plant or other organism
85
define population density
the number of individual organisms in a given are or volume
86
define population explosion
when a population grows so rapdily that it spreads before it can be contained
87
define primary consumer
orgnaism that obtains energy by eating plants
88
define pioneer community
the first species to colonize a barren or distrubed habitat and initiate primary succession
89
define phenotye frequency
the proportion of a poulation with a particular phenotype
90
what does a rectangle shaped age pyramid represent
a stable population
91
what does an upright triangle shaped age pyramid indicate
that there are more births than deaths in the population and therefore the population is growing rapidy
92
what are two factors that decrease a population size
death and emigration
93
what is another name for primary consumers
herbivores
94
define growth rate
the change in the number of individuals in a population over a specific time frame
95
true or false: r selected strategy animals produce close to their biotic potential
true
96
what does environmental resistance determine
the carrying capacity of the habitat
97
define exponential growth phase
stage in the growth of a population in which birth rate is much higher than death rate because compeition for resources is not yet a limiting factor
98
define phenotype
the physical and physiological traits of an organism
99
which is more common in nature: clumped or random distribution
clumped
100
define sustainability
the concept of living in a way that meets our needs without compromising the health of future generations or the health of the planet
101
define carrying capacity
theoretical maximum population size that the environment can sustain over an extened period of time
102
define evolution
change in allele frequencies in a gene pool over time
103
what are 4 processes that change population size
births, immigration, emmigration and deaths
104
when do populations typical exhibit clumped patterns
in areas where food or shelter is most abundant
105
define stationary phase
when the birth and death rates are equivalent
106
define commensalism
a symbiotic relationship in which one partner benefits and the other partner neitehr benefits nor is harmed
107
whats unif9orm distribution
when individuals in a population are evently distribyuted over a defined area
108
define secondary succession
the recolonization of an area after an ecological disturbance where soil is not destroyed
109
what growth pattern would a population that is growing at its biotic potential be expected to follow
exponential
110
what happens when populations share overlapping niches
they compete for limited resources
111
define density independent factor
abiotic factor that limits a habitats carrying capacity
112
whats clumped distribution
when members of a population are found in close prozimity to each toehr in various groups within their habitat
113
define prey
organism that is killed and consumed by another organism
114
what are some characteristics of r selected strategies (4)
- short life span
- early reproductive age
- produce large broods of offspring that receive little or no parental care
- they take advantage of favourable environmental conditions
115
what shape does a logistic growth pattern form
s shape curve
116
what are the 3 types of diversity included in biodiversity
species diversity, genetic diversity and habitat diversity
117
define homozygous
when the 2 alleles at a locus are identical
118
define biodiversity
the variety of all living things and their interactions
119
what do symbiotic relationships typically involve
an organism that lives or feedss in or on another organism
