Ch. 19 Flashcards Preview

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Flashcards in Ch. 19 Deck (34):
1

uniform dispersion-why+ex.

equal distances between every organisms-try to stay as far as possible ex. birds nesting

2

major factors to human population growth

better control of disease, better hygiene/ sanitation, stable food supply

3

problems associated with small populations

inbreeding, vulnerable to extinction

4

three types of population dispersion

uniform, clumped, random

5

random-ex.

where food supply is- snakes

6

survivorship curves

probability that members of a population will survive

7

survivorship curves type l+ex.

very likely to survive younger but less likely when older ex. humans,large mammals,eagles

8

survivorship curves type ll+ ex.

chance of dying/living doesn't change during lifetime ex. birds, squirrels

9

survivorship curves type lll+ex.

very likely to die when young and less likely to die when older ex.salmon, insects

10

limiting factors+ ex.

any factor that restrains the growth of a population ex. space, food, clean water

11

carrying capacity (k)

number of individuals the environment can support over a long period of time

12

density-independent factors+ ex.

reduce the population by the same proportion regardless of populations size ex. weather, floods, fires

13

density-dependent factors+ ex.

include resources limitations and are triggered by increasing population density ex.shortages of food or nesting sites

14

lynx and hare study

Elton thought their cycles were related- more hare= more lynx, less hare= less lynx

15

lynx and hare/ moose and wolves on island royale

small populations are in much more danger than large populations

16

problems with inbreeding

in small pop., can lead to decreased genetic variability which means less likely to adapt

17

calculate pop. density

# of individuals/ unit of area

18

age structure

distribution of individuals among different ages- developed countries have older pop./ developing countries have younger pop.

19

growth rate depends on:

births, deaths, immigration, emigration

20

clumped-why

individuals gathered together- food supply is clumped/flocks or herds

21

calculate GR per capita

birth rate-death rate= growth rate
growth rate/pop.= growth rate per capita

22

exponential model

the population increases rapidly after several generations = exponential growth- "j" shaped
-doesn't work with limiting factors

23

logistics model

like exponential models but takes limiting factors into account

24

agricultural revolution

10,000-12,000 years ago, stabilized-increased food supply

25

demographic transition

industrial development causes economic and social changes that affect population growth rates

26

how are modern humans like hunter gathers?

fishing

27

GR of the world now?

1.1%

28

typical wolf mass (lbs.)

80-120 lbs.

29

% of wolf accuracy

10%

30

Cons to the agricultural revolution

more people= disease spreads easier

31

4 most consumed crops

potatoes
corn
wheat
rice

32

current world population

7.4 billion

33

US pop.

313 million

34

California pop.

38 million