Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 121 > population Ecology > Flashcards

population Ecology Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Ecology

A
  • How organism interact with each other and their environment
  • 5 levels:

1) Organismal ecology
2) population ecology
3) community ecology
4) ecosystem ecology
5) global ecology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

organismal ecology

A

how individuals interact with each other and their environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

population ecology

A

population: a group of individuals of the same species inhabiting a specific area at the same time
- population ecologists focus on how population size changes with time and location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

distribution

A

where organisms are found

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

abundance

A

how many organisms are found in a given area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

factors that affect abundance and distribution

A

1) dispersal ability(physical + climatic barriers_
- bodies of water, mountain ranges, etc
- organism can only tolerate certain temperatures + conditions

2) biotic factors: (living AND once-living)
- tree coverage
-food requirements
- predators
competitors

3) abiotic factors: (non-lining)
- light intensity
- temperature
- water availability
- geographical structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

niche

A

an organisms range of tolerance to abiotic conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

limits of tolerance

A

the upper and lower limits to a range of particular factors (temperature, salinity, light intensity, etc) within which an organism can survive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

population size

A

number of individuals in a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

population density

A

number of individuals in a defined area or volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

estimating population size using Lincoln-Peterson Method (eqt)

A

N=(Mn)/m

N= total population size
m= number of marked individuals in recapture (2nd sample)
n= total individuals in recapture (2nd sample)
M= number of marked individuals in 1st sample
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

assumptions of Peterson method

A

1) population is closed (N is constant)
- no births, deaths, movement of individual in and out

2) all individuals in the population have the same chance of being caught in the first sample
3) marking individuals does not affect their catchability
4) individuals do not lose marks between the two sampling periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

range of tolerance

A

range of conditions within which an organism can survive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how to determine per capita births and deaths

A

b= per capita birth rate, B= births, N= total population, d= per capita death rate, D=deaths

b=B/N
d=D/N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

per capita growth rate (r)

A

r=b-d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the two models of population growth?

A

exponential growth model

logistic growth model

17
Q

exponential growth

A 
- J-shaped curve
dN/dt=rN
- 'r' is constant
 population size/density
r/growth reate= DENSITY-INDEPENDANT
- as the number of individuals added to a population gets larger the population size (N) get larger
   - the amount added depends on r
18
Q

when does exponential growth occur

A
  1. when a FEW INDIVIDUALS found a new population in a new habitat and resources are plentiful
  2. population goes through a bottleneck and is starting to recover with a FEW surviving individuals and resources are plentiful
19
Q

logistic growth

A
  • s shaped curve
  • more realistic
    growth rate levels off to a carrying capacity (K)
  • at K, growth rate= 0
    -DENSITY-DEPENDANT

dN/dt = rN((K-N)/K)

trend:

  1. initially growth in exponential
  2. over time, N increases to the point where competition for resources or other density-dependent factors begins to occur = growth rate declines
  3. population is at the habitat’s carrying capacity, growth rate = 0
20
Q

carrying capacity (K)

A
  • the max population size that a particular environment can support over a period of time
  • not constant (depends on food, space, water, nesting sites, etc)
  • can change with time and location
21
Q

what are two factors that prevent populations from growing indefinitely?

A

1) density-dependent factors: changes in intensity as a function of population size and they are usually biotic
ie,
- intraspecific competition for the same limited resources=less energy for reproduction=decrease reproductive success= decrease per capita birth rate and increase the death rate
- predation
- toxic wastes
- disease and paratism

2) density-independent factors: alter birth and death rates regardless of the # individually in the population. involve changes in the abiotic environment
ie, hurricanes, volcanoes, floods, cold snaps

22
Q

life history traits

A

an organism’s life history refers to the quantification of stages it goes through in its lifetime:
birth-> growth-> reproduction
-> death

ex:

  • age specific survivorship
  • age @ first reproduction
  • fecundity
  • size of offspring
  • growth rate
  • reproductive lifespan
  • sex ratio of offspring
23
Q

what is a life table?

A

summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime

24
Q

age class

A

group of individuals of a specific age

25
Q

cohort

A

group of individuals of the same age that can be followed through time

26
Q

survivorship

A

the proportion of offspring that can survive to a particular age

27
Q

survivorship curves

A

graph depicting the % of a population that survives to different ages

28
Q

Types of survivorship curves

A

I : survivorship is high then drops dramatically in old age
- ie: humans

II: linear, species where individuals have about the same probability of dying in each year
- ie: blackbirds

III: high death rates earlier in life but then high survival rat later in life
- ie: larvae

29
Q

what are fitness trade-offs?

A

resources are limited-
natural selection can not maximize all the life history traits simultaneously
ie: an animal that gives birth to many offspring will not likely be able to provide a lot of parental care due to limited resources (energy, nutrients) thus cannot devote that same energy towards her own survivorship

30
Q

clutch size

A

egg laid

31
Q

fecundity

A

avg # of female offspring produces by a single female I the course of her lifetime

32
Q

net reproductive rate

A

the growth rate of a population per generation

- indicates whether a pop is increasing or decreasing

33
Q

the general relationship between fecundity and survivorship

A

1) low fecundity -> high survivorship (invest resources in traits that aid their own survival
- few, expensive offspring
- K selected

2) high fecundity -> low survivorship
- many cheap offspring
- r selected

34
Q

K-selected organisms are…

A

adapted to stable environments, where competition is high populations tend to hover near “K”

ie: elephants whales

35
Q

K-selected life history traits

A 
- longer-lived species
often type 1 survivorship
reach sexual maturity more slowly
- few, large offspring
well cared for (more parental care)
- larger body size at birth
- often. extensive parental care
-multiple reproductive events 
Good competitors
36
Q

r-selected organisms are…

A

adapted to unstable/unpredictable environments

ie: dandelion, frogs, salmon, insects

37
Q

r-selected life history traits

A
  • short lifespan
  • type 3 survivorship
  • reach sexual maturity quickly
  • typically reproduce only once
    produce large numbers of SMALL offspring (so some survive)
  • provide little care (quantity over quality)
    maximize “r” (growth rate)
  • little to no parental care
  • ## poor competitors
38
Q

in reality organism demonstare …(k-selected/r-selcted)

A

NEITHER! it’s an intermediate between the two

39
Q

population size equation

A

birth-deaths+immmigrants-emmigrants

Biology 121 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions