Ecology Terms In Ch 5-10 Of Env. Science Book

Front 1

gene:

Back 1

a unit of heredity

Front 2

allele:

Back 2

an alternative form of a gene

Front 3

evolution:

Back 3

a change in allele frequency through time

Front 4

fact:

Back 4

something with real, demonstrable existence

Front 5

genetic drift:

Back 5

random allele frequency fluctuations in finite populations

Front 6

natural selection:

Back 6

individuals best able to survive and reproduce contribute MORE genes to next generation
--> if they are beneficial than they are more common.

Front 7

what is the cause of genetic drift?

Back 7

the alleles in any generation are a sample of the alleles of a previous generation.

Front 8

"descent with modification":

Back 8

all species descended from a single ancestor
natural selection leads to species divergence.

Front 9

habitat:

Back 9

physical area where an organism lives
--> characterized by physical and chemical features

Front 10

community:

Back 10

all organisms that live in a particular area

Front 11

niche:

Back 11

what a species does. their role.

Front 12

commensalism

Back 12

beneficial/neutral (fruit flies)

Front 13

mutualism

Back 13

beneficial/beneficial

Front 14

parasitism

Back 14

beneficial/negative

Front 15

predation

Back 15

beneficial/negative

Front 16

symbiosis:

Back 16

a close physical association b/t 2 species for at least some part of the life cycle
ex: mutualism, parasitism, and comensalism

Front 17

co-evolution:

Back 17

joint evolution of 2 or more species due to close interaction


as a predator evolves, prey must evolve in order to keep predator from wiping them out

Front 18

prey defenses:

Back 18

camouflage, warning coloration, mimicry, moment-of-truth defenses

Front 19

predator responses:

Back 19

an adaptation that protects prey may select for predators that can overcome adaptation
--> stealth, camouflage, avoidance of chemical repellents

Front 20

biomes:

Back 20

broadly defined life zones with similar traits, climates, topographies, diversity, soil conditions, & biological communities

Front 21

temperature and precipitation:

Back 21

often define type of biological community

Front 22

seasons:

Back 22

earth's axis is inclined,
the greater the distance form the equator the more defined seasonal changes

Front 23

tropical rainforests:

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wettest and warmest, high precipitation, warm temperatures

Front 24

tropical seasonal rainforests:

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very warm temperatures, sometimes droughts, variable precipitations.

Front 25

scrublands:

Back 25

warm and dry,
shaped by intense fires,
biodiversity "hot-spots"

Front 26

savannas & grasslands:

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too little rainfall for a lot of trees,
vegetation is sometimes adapted to droughts and fires

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temperate grasslands:

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high biodiversity, thick, organic-rich soil,
some converted to farmlands

Front 28

deserts:

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hot or cold, always dry, organisms adapted to drought and extreme weather,

Front 29

biodiversity:

Back 29

the variety of living things.

Front 30

species diversity:

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number of different kinds of orgnisms w/ in an ecosystem

Front 31

ecological diversity:

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complexity of a biological community (# of niches, trophic levels)

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genetic diversity:

Back 32

allelic variety with in a species

Front 33

endemic species:

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occur only in one geographic region

Front 34

benefits of biodiversity:

Back 34

foods, drugs and medicines, ecological services.

Front 35

biodiversity extinction:

Back 35

greater NOW than ever.
it is a natural process... 99% of all species that ever lived are extinct
1 species naturally lost every decade

Front 36

current mass extinction:

Back 36

25 species/ a day

75% caused by humans

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human caused extinction because

Back 37

1) Habitat destruction and fragmentation
2) hunting and fishing
3) predator & pest control
4) diseases
5)commercial product and trade
6)pollution
7)exotic species introduction
8) reducing genetic variability