Kategorier: Alle - nitrogen - carbon - organisms - decomposition

af Aresha Bagheri 11 år siden

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Introductory Biology II Concept Map

Organisms depend on various biogeochemical cycles to obtain essential elements needed for survival and growth. The phosphorous cycle provides phosphorous, crucial for nucleic acids, phospholipids, ATP, and other mineral components, primarily through the weathering of rocks and plant uptake.

Introductory Biology II Concept Map

Introductory Biology II Concept Map - Aresha Bagheri

Selection

sexual selection
females chosing males based on their phenotype

2 components

females choose

males compete

ex.peacocks

directional selection
extremes are favored

ex. peppered moths

stabilizing selection
intermediates have advantage
response to selection
selection differential

measures intensity or strength of selection

heritability

proprotion of phenotypic variation that has a genetic basis

rated from 0 to 1, 0 is environmentally based, 1 is genetically based

artificial selection
the selective breeding of domesticated plants and animals to encourage the occurance of desirable traits

ex. corn crops

natural selection
individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits

ex. antibiotics

Global Warming

future effects...
biological impacts

species extinction

coral bleaching

earlier spring events

altitudinal/poleward shifts in species ranges

warming oceans

more intense hurricanes

melting ice caps
rising sea levels
change in precipitation
caused by...
depletion of the ozone layer

CFC's deplete ozone

greenhouse gasses

human activity

such as CO2

The greenhouse effect - the trapping of heat in the atmosphere by certain greenhouse gasses.
Water vapor
CFC's

produced from cleaners, aerosols, refridgeration and cooling

nitrous oxides

combine with sulfur dioxide to produce acid rain

produced naturally and man made

CH4

produced in rice paddies, wet agriculture, intestinal system of cows, floors of oceans

CO2
The increasse of the global average temperature on Earth
by the end of the century about 4 degrees Celcius hotter
1 degree Celcius hotter on average

Population Genetics

Hardy-Weinberg Equilibrium
p+q=1, p²+2pq+q²=1
If Hardy Weinberg conditions are not met, then the population is evolving.
Allele and genotypic frequencies remain the same from generation to generation in a population in which there is...

no selection

selection - differential reproduction among different phenotypes within a population

response to selection depends on the selection differential and the heritability of the trait in question

random mating

asexual reproduction

offspring are genetically identical to the parent

positive assortive mating

increases homozygosity only at the locus for which the choice occurs

Inbreeding - mating between relatives - not random mating

selfing - most severe form of inbreeding

heterozygosity is halved between generations

leads to inbreeding depression - decrease of vigor or reproductive success due to inbreeding

no migration

migration (gene flow) - the movement of genes between populations

allele frequencies change in the direction of the doror/source population due to migration

p(M)=p(I)M+p(R)(1-M)

migration tends to eliminate existing genetic differences between populations

migration rate - the proportion of immigrants in a population after migration

no genetic drift

genetic drift - random changes in allele frequencies from generation to generation

bottleneck effect - random changes in allele frequencies within a population due to dramatic reduction of population size

reduction in size is either caused by some catastrophic events, or only the frequencies of those loci are considered that are not under selection

founder effect - random changes in allele frequencies in a population during colonization

founder effect occurs within the same generation

genetic drift results from sampling error in a population with limited size

no mutation

mutation - random change in the genetic code

majority of mutations are detrimental

mutation rates for many genes can vary from one out of ten to one hundred thousand

the ultimate source of genetic variation in a population

Genetic Variation in a Population
allele frequency

the proportion of a certain allele within a population

allele frequency=gene frequency=gametic frequency

gene pool

the set of all alleles at all loci in a population

Energy Flow in Ecosystems

An ecosystem is a group of organisms that are connected by energy and mineral flow.
Energy is transferred from one trophic level to the next
handling time - the time it takes from capture of food item by a foraging organism to digestion
energy flow is non-cyclic
the sun is the primary source of energy

producers

net primary productivity

gross primary productivity minus plant respiration

gross primary productivity is the total photosynthesis per unit area per time

plant growth per unit area per unit time

Only .02% of the sun's energy is captured by plants

herbivores

carnivores

top carnivores

heat energy lost

decomposers and detritivores

Only 1/3 of energy is transferred from one trophic level to the next.

The rest of the energy is lost as heat.

Human Evolution

evolution - changes in allele frequencies within a population
trends in human evolution
development of language paralells the evolutionary process
longer lifes span and and longer dependency
brain size in Hominid lineage increased dramatically from 500 to 1350 cubic centimeters
The oldest fossil remains of human ancestors were found in Africa.
then spread to the Middle East

Domestication first occured in the Middle East an South Europe 11,000 years ago

to Asia

60,000 years ago

to Australia

to North America via land bridge

to South America

to Europe

Hominids (Australopithicus and Homo) and apes diverged from a common ancestor 5 million years ago.
The oldest Hominid was Ardipithecus ramidus

Australopithecus anamensis

A. afarensis

Homo rudolfensis

H. habilus

was a toolmaker

H. erectus

Turkana boy

1 million years ago

H. sapien

H. sapien sapien (modern human)

evolved 50-35,000 years ago

H. sapiens (Neanderthals)

humans have 3% neanderthal DNA

died out 22,000 years ago

evolved 300,000 years ago

Lived 2 million years ago to 1.8 million y.a.

Homo genus evolved 2 million years ago

A. africanus

Taung child

discovered in South Africa

A. robustus

2 million years ago

A. boisei

2.5 million years ago

3 million years ago

Lucy was an A. afarensis

discovered in Hadar, Ethiopia

4 million years ago

Ardipithecus was bipedal

Human DNA is 98.8% similar to the DNA of chipanzees

Biogeochemical Cycles

The Nitrogen Cycle
Plants use two inorganic forms of nitrogen - ammonium and nitrate - and amino acids. Bacteria use these forms too as well as nitrite, animals can only use organic forms of nitrogen.

the nitrogen cycle

terrestrial cycling

reactive N gasses

denitrification

fertilizers

Industrial fixation

aquatic cycling

NO3- in the water

N2 in atmosphere

Reservoirs of nitrogen include...

biomass

surface water and groundwater

sediment

the soil

the atmosphere (80%)

The Water Cycle
Water is essential to all organisms, and its avaliability influences the rates of ecosystem processes.

Water cycle

Transpiration

Runoff and groundwater

Percolation through soil

Precipitation

Condensation of water vapor into clouds

Evaporation by solar energy

1% of water is contained in lakes, rivers, and groundwater (negligible amount in atmosphere).

2% Of water is contained in polar ice caps.

The oceans contain 97% of water in the biosphere.

Liquid water is the primary physical phase of water.

The Carbon Cycle
Carbon forms the framework of the organic molecules essential to all organisms.

the carbon cycle

burning of fossil fuels

phytoplankton

consumers

cellular respiration

Photosynthesis

CO2 in atmosphere

Major reservoirs of carbon include...

sedimentary rocks (the largest reservoir)

the atmosphere

plant and animal biomass

the oceans

sediments of aquatic environments

soils

fossil fuels

Carbon is available in the form of CO2 to plants, which convert it to organic forms that are used by other organisms.

The Phosphorous Cycle
Organisms require it for nucleic acids, phospholipids, ATP and mineral components.

phosphorous cycle

leaching into aquatic environments

decomposition

plant uptake

runoff

weathering of rocks

geological uplift

reservoirs include...

organisms

oceans

soil

sedimentary rocks

Most important inorganic form is phosphate, which plants use to create organic compounds.