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Ch 5 exam
APES
31
Environmental Studies
12th Grade
09/24/2008

Additional Environmental Studies Flashcards

 


 

Cards

Term
development of life on earth
Definition

first phase - chemical evolution of the organic molecules, bipolymers, & systems of chemical reactions needed to form the first cells ~1 bill yrs ago

 

second phase - biological evolution from single celled prokaryotic bacteria to single-celled eukarytoic to multicellular ~3.7 bill yrs ago

 

 anaerobic bacteria - photosynthetic bacteria (cyanobacteria) - aerobic bacteria - single-celled eukaryotes - multi-celled eukaryotes

Term

fossils

Definition

mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds or impressions of such items

 

 

Term
biological evolution
Definition
major driving force of adaptation in environmental conditions
Term

theory of evolution

Definition
all species descended from earlier, ancestral species
Term
gene pool
Definition

collection of genes or genetic resources potentially available to members' offspring in the next generation

 

first step in evolution is the development of genetic variability

Term
mutations
Definition

random changes in the structure or number of DNA molecules in a cell that can be inherited by offspring

 

1. exposure of DNA to external agents such as radioactivity, X rays, and natural/human-made chemicals (mutagens)

 

2. random mistakes that occur in coded genetic instructions

 

-the only source of totally new genetic raw material

Term
natural selection
Definition

3 conditions necessary for evolution by NS:

 

-genetic variability

-trait must be heritable

-must lead to differential reproduction: enable indiv. with the trait to leave more offspring that other members of the pop

 

Term
coevolution
Definition
when populations of two different species interact over a long time, changes in the gene pool of one species can lead to changes in the gene pool of the other
Term

ecological niche

Definition

species way of life or functional role in a community or ecosystem and involves everything that affects its survival and reproduction

 

includes the adaptations/adaptive traits its members have acquired through evolution

 

includes species range of tolerance

 

includes the types and amounts of resources the species uses, how it interacts with other living and nonliving components of the ecosystems, and the role it plays in the energy flow and matter cycling

Term
habitat
Definition
physical location where a species lives
Term
fundamental niche
Definition
full potential range of physical, chemical and biological conditions and resources it could theoretically use if there were no direct competition from other species
Term
realized niche
Definition
part of its fundamental niche in a particular community or ecosystem
Term
generalist species
Definition
broad niches
Term

microevolution

Definition
the small genetic changes that occur in a population
Term
macroevolution
Definition
long-term, large-scale evolutionary changes through which new species form from ancestral species and other species are lost through extinction
Term
specialist species
Definition
narrow niches

have an advantage because they have fewer competitors when evironmental conditions are fairly constant
Term
evolutionary divergence
Definition
a single species diverging into a variety of similar species with specialized niches
Term
Limits to adaptations in nature
Definition
1. change in environmental conditions can lead to adapation only for genetic traits already present in the gene pool of a population

2.even if a beneficial heritable trait is present in a population, the population's ability to adapt may be limited by its reproductive capacity

most of the pop would have to die or become sterile so that indiv. with the trait could predominate and pass the trait on
Term
speciation
Definition
two species arise from one
Term
allopatric speciation
Definition
two phases:
-geographic isolation: different groups of the same population become physically isolated from one another for long periods

-reproductive isolation: mutation and natural selection operate independently in the gene pools of two geographically isolated populations
Term
sympatric speciation
Definition
creation of a new species when groups in a population living close together are unable to interbreed because of a mutation or subtle behavioral changes
Term
extinction
Definition
an entire species ceases to exist

99.9% of all the species that ever existed are now extinct
Term
background extinction
Definition
as lock environmental conditions change, a certain number of species disappear at a low rate
Term
mass extinction
Definition
significant rise in extinction rates above the background level
Term
mass depletion
Definition
extinction rates are higher than normal but not high enough to classify as a mass extinction
Term
adaptive radiation
Definition
periods of recovery in which numerous new species evolved to fill new or vacated ecological roles or niches in changed environments (1-10 mill yrs)
Term
biodiversity
Definition
species minus extinction; planets raw material for future evolution in response to changing conditions
Term
artificial selection
Definition
select one or more desirable trait in the population of a plant or animal and use selective breeding to end up with pop of the species containing large numbers of indiv with the desired trait

results in many domesticated breeds or hybrids of the same species, all originally developed from one wild species
Term
genetic engineering/gene splicing
Definition
set of techniques for isolating, modifying multiplying and recombining genes from different organisms; enables scientists to transfer genes btw different species that would never interbreed in nature

results in a genetically modified organism (GMO) or transgenic organism

takes about half as much time to develop a new crop or animal variety

trial and error process; average success rate of 1%
Term
biopharming
Definition
using genetically engineered animals to act as biofactories for producing drugs, vaccines, antibodies, hormones, industrial chemicals such as plastics and detergents and human body organs
Term
human success
Definition
two evoutionary adaptations: a complex brain and strong opposable thubgs that allow us to grop and use toools better than the few other animals that have thumbs
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