unit 4 Population Flashcards

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1
Q

What is ecological succession?

A

the process of change by which the biotic communities replace each other and by which the physical (abiotic) environment becomes altered over a period of time is called ecological succession

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2
Q

identify the two types of succession.

A

first-degree (primary succession ) and second-degree (secondary succession)

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3
Q

what are the characteristics of first-degree succession?

A
  • # of species increases rapidly at first
  • colonized by pioneer species (they start succession)
  • pioneer species are rapid growers and capable of surviving harsh environments
  • begins with soil formation from bare rock
  • takes a very long time to reach the climax community (dictated by the biome) and stops at the climax community
    examples:
    landslides mountains fall apart
    retreating glaciers
    lava from volcanoes
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4
Q

What are the characteristics of second-degree succession ?

A
  • reestablishment after ecological disturbance (catastrophe)
  • takes a shorter time because soil formation has already occurred
  • organic matter already present
  • stops at Climax community
  • previously established ecosystem
    Examples:
    1. Forest fires… controlled or natural
    2. clear-cutting of forests
    3. floods
    4. urban development
    5. avalanche
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5
Q

what is the Hardy- Weinberg equilibrium theory?

A
  1. it allows us to predict allele frequencies in living populations
  2. it tells us that allele frequencies tend to remain constant from generation to generation unless acted on by outside forces = evolution
  3. it allows us to predict what phenotypes/traits will be in a given population now and in the future.
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6
Q

Hardy showed that allele frequencies in a population will remain the same from one generation to the next, as long as the five conditions are met what are they?

A
  1. the population is large to ensure no statistical flukes
  2. random mating (i.e organisms with one genotype do not prefer to mate with organism with a certain genotype)
  3. no mutations.
  4. no migration between populations (i.e the population remains static)
  5. no natural selection (i.e no genotype is more likely to survive than another)
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7
Q

what is symbiosis?

A

survival of one species might depend on another species
1. commensal
2. parasitic
3. mutalisitc

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8
Q

what is mutualism and what are the benefits?

A

Mutualism most popular relationship. Organisms and the ecosystems and services that
they provide for take care of the place so that 10,000 generations from now, there will
still be a place”. Mutualism has a strong place in the way that ecosystems survive.

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9
Q

what is commensalism? and what are the benefits

A

In commensalism, one organism benefits while the other is unaffected. For example, one organism can provide an essential growth factor, such as a vitamin, for another organism. This type of cross-feeding is common in soil organisms.

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10
Q

what is parasitism and what are the benefits?

A

parasites play a role in regulating populations that have high densities.

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11
Q

what is competition

A

A rivalry of two or more parties over a shared requirement for a resource in limited supply

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12
Q

what is Gause’s competitive exclusion principle?

A

“when individuals compete, the organisms alter their niches so as to try to coexist”. No one wants to risk getting hurt. So, for instance, owl and hawk change the time of day they hunt. Plants change when they photosythesize or how fast they reproduce

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13
Q

what are the two types of competition

A

interspecific and intraspecific

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14
Q

what is interspecific competition ?

A
  • competition between members of different species
    i.e same prey
  • this type of competition can lead to extinction; can lead to greater adaptions
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15
Q

What is the intraspecific competition?

A

competition between members of the same species i.e after the same mate, space, habitat
this type of competition leads to the evolution of better adaptations within a species.

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16
Q

What is predator-prey population interaction?

A

Predator kills its prey immediately. Predator is usually big
in size. Predator’s biotic potential is usually very low.

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17
Q

what are some reintroduction considerations someone must think of before releasing animals into an environment?

A
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18
Q

Factors affecting allele frequency and genetic diversity in the population? What is the impact on Genetic diversity in the population?

A

Has a subtle effect because rates are generally extremely slow, and the change in allele frequency will be, at most, the same order.
Brings new alleles into the population, either increasing recessive allele or decreasing dominant allele

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19
Q

How does migration affect allele frequency? And what is the impact on Genetic diversity in the population?

A

Migration of individuals from one population to another can change allele frequencies and even introduce new alleles.
- increases genetic diversity within a population however decreases diversity between populations.
- higher rates of migration lead to higher genetic diversity increasing the longevity of the population.

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20
Q

what are the two ways of getting small populations?

A

bottleneck effect or founders effect

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21
Q

what is the bottleneck affect?

A

rapid decline in population due to the anthropogenic or natural catastrophes that kill off most of the population usually who causes this are humans

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22
Q

What is the founder’s effect?

A

A new population is “founded” with a small # of individuals from a parent population. Become separated from the main population ( voluntarily or accidentally), not through death

23
Q

What is genetic drift?

A

loss of dominant, recessive allele
- a mating event where, chance plus the fact that few are mating, an allele is lost; this is compounded if the mating pair only produce one offspring at a time

24
Q

What is inbreeding?

A

A selective breeding method in which two individuals with identical or similar sets of alleles are crossed.

25
Q

What is natural selection and what impact on genetic diversity does it have?

A

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

removes alleles from populations changing allele frequencies lowering genetic diversity

26
Q

What is non-random mating, and how does it impact genetic diversity in a population?

A

mating between individuals of the same phenotype or by those who live nearby
- decreases genetic diversity as some alleles are lost, changing allele frequencies

27
Q

What is non-random mating, and how does it impact genetic diversity in a population?

A

Mating between individuals of the same phenotype or by those who live nearby
- decreases genetic diversity as some alleles are lost, changing allele frequencies

28
Q

methods of preserving or improving genetic diversity in the population

A
  1. catch and release programs, captive breeding programs
  2. reintroduction, and relocation programs
    must make breeding and habitat considerations
  3. put on the endangered species list so it can receive funding for protections
29
Q

What are ways of preserving or improving populations?

A
  • catch and release programs
  • captive breeding programs
  • reintroduction
30
Q

methods of preserving or improving genetic diversity in the population

A
  1. catch and release programs, captive breeding programs
  2. reintroduction and relocation programs
    must make breeding and habitat considerations
  3. put on the endangered species list so it can receive funding for protections
31
Q

What is the difference between open and closed populations?

A

open: affected by all four factors, open to genetic material from the outside
closed: affected only by births and deaths; closed to genetic material from the outside

32
Q

What are some density-dependent factors or biotic factors?

A
  • food supply
  • disease
  • parasitism
  • competition- both types
  • predation
33
Q

What are some density-independent factors abiotic factors?

A
  • rainfall
  • temperature
  • acidity + all other abiotic factors
  • catastrophic events such as flooding, fire, drought, tsunami, earthquake or volcanic eruption
34
Q

What is immigration?

A

Migration to a new location

35
Q

What is emigration?

A

movement of individuals out of a population

36
Q

What is density?

A

Population density is the # of individuals that live in a defined area.

37
Q

Fecundity?

A

reproductive value
- how someone is designed to produce babies

38
Q

What is fertility?

A

How many offspring were made

39
Q

what is carrying capacity?

A
  • maximum population density (saturation density) that the resource base in the environment can support
40
Q

What is biotic potential?

A

This refers to the reproductive fitness (fecundity) of an organism. If Bp is low, produce a few offspring each season or every couple years. If Bp is high, leave many offspring each season or mate multiple times. a year

41
Q

What is biotic potential?

A

This refers to the reproductive fitness (fecundity) of an organism. If Bp is low, produce a few offspring each season or every couple of years. If Bp is high, leave many offspring each season or mate multiple times. a year

42
Q

What is environmental resistance?

A

-causing death
- resisting growth
-compeition
-predation

43
Q

What is exponential growth?

A

J-shaped growth curve for r-stragesists

44
Q

k-selected

A

Population size:
- limited by carrying capacity (k)
- density-dependent
- relatively stable
- appear late in succession
ORGANISMs
- larger, long livered
- produce fewer offspring
- provide greater maternal care for offspring
- CLIMAX COMMUNITY
- affected by density dependent

45
Q

r-selected

A

Population size:
- limited by reproductive rate (r)
- density-independent
-relatively unstable
- appear early in succession (pioneer species)
ORGANISMS
- smaller, short-lived (g)
- produce many offspring
- provide no MATERNAL CARE for offspring

46
Q

What is a rapid-growth population pyramid?

A

It looks like a typical pyramid with a large base that gets smaller as you ascend
this type of population typically has poor health care and short life expectancies. Mostly found in under developed and developing countries

47
Q

what is a slow or stable growth population pyramid?

A

there is little change in the lower sections of the pyramid. Only after the upper ages do you see a marked change in population. This type of population pyramid is mostly found in developed countries sometimes middle income countries . These countries have good health care, long life expectancies

48
Q

what is negative or declining growth population growth?

A

the middle section of the pyramid is the widest section. This type of population pyramid is mostly found in developed countries. These countries have good health care, long life expectancies and stable governments
however, their birth rates are lower than needed to replace the population

49
Q

What are deciduous trees

A

a tree that sheds and regrows its leaves in response to seasonal changes, like ginkgo
- think fall time

50
Q

What are coniferous trees?

A

term used to refer to trees that produce seed-bearing cones and have thin leaves shaped like needles
- pined trees all year around

51
Q

What is genetic drift?

A

Refers to the random fluctuation of allele frequencies in a population over time due to chance events. It usually occurs in a small population
- reduces overall genetic diversity

52
Q

What is a gene pool?

A

The total collection of genes, including all the alleles, within a population or a specific species.
- represents the sum total of all genetic material available for inheritance

53
Q

what is gene flow?

A

Also known as migration, it is the transfer of genetic material between populations. It occurs when individuals move from one population to another and breed with individuals in the new population