Competency 0012 by fionan

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									ROUGH DRAFT

Competency 0012

1.   Understand concepts, principles = applications of classical and molecular genetics.
     A. Analyze the significance of Mendel’s pea experiments.
                  Brought an experimental and quantitative approach – science as a process.
                  By law of segregation, 2 alleles for a character are packaged into separate
                     gametes.
                  By law of independent assortment, each pair of alleles segregates into
                     gametes independently.
                  Mendelian inheritance reflects rules of probability.
                  Discovered the particulate behavior of genes.

     <Dominant allele: in a heterozygote, the allele is fully expressed.
     <Recessive allele: in a heterozygote the allele that is fully masked.

     Mendel cross-pollinated purple flowering pea plants with white flowering pea plants.


<Law of segregation: Independent assortment: specific application of the same general rules of
probability for genetic analysis.

II. Analyze genetic inheritance problems involving genotypic and phenotopic frequencies.
     <Phenotype: physical and physiological traits of an organism (appearance).
     <Genotype: Genetic make-up of an organism, .the type of genes an organism has for a trait

     An organism’s appearance does not always reveal its genetic composition.


                                       Population Genetics

Key – vocab
Key – concepts & principles

1. Allele – an alternate form of a gene
2. Gene pool – the total aggregate of genes in a population at any one time. It consists of all
alleles at all gene loci in all individuals of the population.
3. Gene – a discrete unit of hereditary information consisting of a specific nucleotide sequence
in DNA that codes for a trait.
4. Genetic drift – changes in the gene pool of a small population due to chance.
5. Genotype – the genetic make-up of an organism
6. Hardy-Weinburg Theorem – states that frequencies of alleles and genotypes in a
population’s gene pool remain constant over the generation unless acted upon by agents other



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than sexual recombination. (The sexual shuffling of alleles due to meiosis and random
fertilization has no overall effect on the overall genetic structure of a population. Provides a
baseline for tracking deviations in a population over a succession of generations - (describes a
gene pool in equilibrium) - non-evolving population)

7. Microevolution – a generation-to-generation change in a population’s allele or genotype
frequencies.

8.   Five causes of microevolution
     A. Genetic drift – changes in the gene pool of a small population due to chance.
     B. Gene flow-genetic exchange due to the migration of fertile individuals or gametes
between populations.
     C. Mutation – a change in an organism’s DNA. For any one-gene locus, mutation alone
does not have much quantitative effect on a large population. Although mutations at a particular
gene locus are rare, the cumulative impact of mutations at all loci can be significant.
     D. Natural selection – differential success in the reproduction of different phenotypes
resulting from the interaction of organism with their environment.

Competency 0013

Analyze adaptations as products of variation and natural selection.

Natural selection – Differential success in the reproduction of different phenotypes resulting
from interaction of organisms with their environment.

Variations result from:
    mutations
    genetic recombination (sexual reproduction)
    environmental selection effects

Effect of Selection:
     Stabilizing selection acts against extreme phenotypes and favors the more common variants;
        i.e., stabilizes the status quo, i.e. human birth weights in 3-4 kg range. Smaller and larger
        babies have a greater infant mortality.
     Directional selection is most common during environmental changes or through migration.
        This shifts the frequency curve for a variation by favoring initially rare phenotypes, i.e.,
        size of bears in Europe increased with each glacial period of ice ages and decreased
        during warmer interglacial periods.
     Diversifying selection – occurs when environmental conditions are varied in a way that
        favors individuals on both extremes, i.e., finch population with two bill sizes.

Competency 0013

Analyze proposed mechanisms of evolution: (e.g., embryology, biochemistry, anatomy) in terms
of evolutionary theory.



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    Biogeography – geographical distribution of species
    Fossil record provides fossil evidence of changes in organisms over time
    Comparative anatomy - provides anatomical evidence of evolution – homologous structures
       are similar characteristics resulting from common ancestry, i.e., forelimbs of mammals
       arise from the same embryonic skeletal structures but are modified for different uses.
    Comparative embryology – closely related organisms go through similar stages in
       embryonic development, i.e., embryos show homology during development that are
       modified as adult structures (gill slits)
           - Ontogeny – the embryonic development of an organism
           - Phylogeny – evolutionary history of a species or related organisms
    Molecular biology – tools and techniques used to study evolutionary relationships based on
       DNA and proteins. A common genetic code among organisms is evidence that all life is
       related.

Competency 0014

Factors that contribute to speciation - origin (evolution) of a new species

Allopatric speciation is caused by:
          Geographical isolation – divides a population into two isolated populations which
             eventually diverge
          Adaptive radiation – evolution of several species with diverse adaptations from a
             common ancestor. Occurs in association with island chains such as the Galapagos
             Islands.
Sympatric speciation – occurs when species originate in the geographical midst of the parent
species. Caused by a reproductive barrier between individuals of the mutant and the parent
species.

Factors leading to Reproductive Isolation (the idea that organisms of the same species interbreed
and populations belonging to different species do not interbred)
(Understand that a zygote occurs when the sperm of one organism fertilizes the ova of an
organism of the same species, and restores the diploid number of chromosomes)
          Pre-zygotic barriers to reproduction impede mating between species and prevent
            fertilization of ova when members of different species do attempt to mate
                 o Habitat Isolation – two species that live in different habitats encounter each
                     other rarely (and will prefer mates of their own species)
                 o Behavioral Isolation – courtship behaviors and sexual signals are species
                     specific
                 o Temporal Isolation – Breeding typically occurs at differing times between
                     related species preventing cross species mating
                 o Mechanical Isolation – Related species are anatomically incompatible for
                     mating
                 o Gametic Isolation – Gametes of different species will rarely fuse to form a
                     gamete at all.
           Post-zygotic Barriers occur when a sperm of one species does fertilize an ova of a
             different species, the hybrid zygote will seldom develop into an offspring


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-Post-zygotic Barriers
     - Reduce hybrid viability
     - Reduce hybrid Fertility
     - Hybrid Breakdown.

Competency 015
Taxonomy: Classification of Organisms
I. Linnaeus
     A. Binomial nomenclature
       1. Common
     B. Taxonomy filing system for grouping species (broader to specific)
       1.    Domain
       2.    Kingdom
       3.    Phyla
               Subphyla
       4.    Class
       5.    Order
       6.    Family
       7.    Genus
       8.    Species

   II.      Evolutionary history (Phylogeny)

         Phylogenetic Trees – diagrams that trace evolutionary history
            a) Monophyletic tree – a single ancestor gives rise to all species in that taxon and to
               no species in any other taxon
            b) Polyphyletic – members of a taxon are derived from two or more ancestors not
               common to all members of the taxon
            c) Prophylactic – a taxon excludes species that share a common ancestor that gave
               rise to the species in that taxon

Convergent evolution – adaptations in species from different evolutionary branches may come to
resemble one another if they have similar ecological roles and natural selection has shaped
analogous adaptations
      Analogy – similarity of structure between two unrelated species, attributed to convergent
      evolution
The more removed two structures are the less likely it is they evolved independently (example-
skills of the chimp can be compared to human skills)

III. Classify organisms
     Fossil Record
     Similar characteristics
       Homology (likeness related to shared ancestry)
       Analogy – similarity due to convergent evolution
     Molecular biology compares macromolecules as well as anatomical features
       a) Protein comparisons of amino acid sequences of two species



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       b) DNA, RNA comparisons of genes or genomes of two species
          a. Restriction mapping – uses restriction enzymes to cut a sequence of DNA into
              fragments, electrophoresis separates the sequences based on their length. Two
              samples of DNA can be compared for similarity in the locations of restriction
              sites.
          b. DNA sequence analysis compares the actual nucleotide sequences of DNA
              segments between two species.
       c) DNA Hybridization - Identifying and comparing homologous DNA sequences in two
          species using DNA sequencing. Measures the degree of homology between 2 single
          strands of DNA obtained from different sources
       d) Molecular clock – rate of evolution seems to be constant over time. Analysis of
          mutation rate in proteins and nucleic acids suggests time of divergence from a
          common ancestor.

Competency 015

Taxonomy – the identification and classification of species, the study that arranges organisms in
categories that reflect phylogeny.

Binomial nomenclature – two-part name assigned to each species, the scientific name of a
species consisting of the genus and the species.

Genus – The first word of the binomial name to which the species belongs. Capitalized

Species – The second word of the binomial refers to one species within the genus. The species is
      expressed in lower case. The grouping “species” refers to a specific kind of organism. All
      members of a species possess similar anatomical structures and are able to interbreed.

Taxonomy classification:
   a) Species – groups of a specific kind of organism
   b) Genus – groups of related species
   c) Family – groups related genera
   d) Orders – groups related families
   e) Classes – groups related orders
   f) Phyla – groups related classes
   g) Kingdoms – groups phyla
   h) Domain – groups kingdoms

Taxon – The name of a taxonomic unit at any of the above levels.

Competency 0017

Organisms traditionally have been classified into a five kingdom system:
    Monera
    Protista
    Plantae


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     Fungi
     Animalia
In the last decade, understanding of evolutionary history suggests to scientists an expanded
classification system that places organisms into 3 domains, a taxonomic level above kingdom:

                Domain Bacteria
                                       {Prokaryotes
                Domain Archea
                Domain Eukarya
                    o Protista
                    o Plantae
                    o Fungi
                                       {Eukaryotes
                    o Animalia

Characteristics of Archaeobacteria
1. Extreme environments
    a. Salt water
    b. Boiling hot springs
2. Differences between bacteria & eukarya
    a. Molecular level and nucleic acids

3. In Archaea, absence of:
     a. Nucleic envelope
     b. Membrane-enclosed organelles
     c. Peptidoglycan in cell wall

4.   Present
     a. Membrane lipids
     b. RNA polymerase (several kinds)
     c. Amino Acid – methionine
     d. No coding (introns) parts of genes – (present in some genes)
     e. Response to antibiotics – growth not inhibited (streptomycin & chloramphenicol)


Competency 0017

Viruses
    a. Characteristics
       1) Nucleic acid (DNA & RNA) enclosed protein coat capsid
       2) Diverse in shape
       3) Common structural motifs
       4) No ribosome or equipment to make own protein
       5) Limit host range – lock & key fit between surface proteins

Competency 0017

Monerans – prokaryotic organisms commonly called bacteria.


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     a. Characteristics:
        1) Adaptable
        2) Double-stranded circular DNA
        3) Divide by binary fission – asexual reproduction
        4) Rapid proliferation in favorable conditions.

Differences
       1) Eukarya have linear DNA; translates large amount protein
       2) ↓ protein than virus.


Competency 0017

Fungi are eukaryotes and most are multicellular. Absorptive nutrition enables fungi to live as
decomposers and symbionts. (Except for Yeasts, which are unicellular.) The bodies of fungi are
constructed of units called hyphae (ingulae, hypha). Hyphae are minute threads composed of
tubular walls surrounding plasma membranes and cytoplasm. The cytoplasm contains the usual
eukaryotic organelles. The hyphae form an interwoven mat called a mycelium -the “feeding”
network of a fungus.

Hyphae
Plasma membranes
Cytoplasm
Eukaryotic organelles
Mycelium

Competency 0017

Protists are the earliest eukaryotic descendents of prokaryotes. Protists are the most diverse
kingdom of all eukaryotes. Protists vary in structure and function more than any other group of
organisms. Most of the approximately 60,000 known species are unicellular in structure, but
there are some colonial and multicellular species. Because most protists are unicellular, they are
justifiably considered to be the simplest eukaryotic organisms. At the cellular level, many
protists are exceptionally complex – the most elaborate of all cells.

By itself a protist is an organism as complete as any whole plant or animal. Most are aerobic in
their metabolism, using mitochondria for cellular respiration. Most are motile, having flagella or
cilia at some time in their life cycles. They are found almost anywhere there is water.

Competency 0018

I. Non-vascular plants (algae, mosses e.g.)
    A. Structural characteristics
       1. Many grow in tight pack
       2. Spongy quality
       3. Able to absorb and retain water



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        4. Short and hug the earth
        5. Elongated cells or filaments called rhizoids for the root system.
        6. Stem like and leaf like appendages from the upper part

      B. Life cycle-Alteration of generations
               a. Haploid cell
               b. Diploid cell
               c. Zygote

      C. Functions
               a. Stabilizing atmospheric CO2
                      1) Climate stabilization
               b. O2 production (algae)
               c. Water movement
                      1. Imbibed like sponges
                      2. Diffused throughout plant

II. Vascular plants (Ferns, Angiosperms, Gymnosperms)
              A. Ferns: The first Vascular Plants having a vascular system but lack true roots
                  and true leaves
                       i. Xylem – tissue that carries water to all parts of the plant
                      ii. Phloem – tissue that carries nutrients and products of photosynthesis to
                          all parts of the plant
              B. Seed Plants – Adaptations are roots, stems, leaves and seeds allow these plants
                  to survive in land environments
                       i. Gymnosperms – cycads, gingkos, conifers
                               1. have naked seeds contained in cones
                      ii. Angiosperms – flowering plants – reproduce sexually with flowers in a
                          process called pollination
                               1. seeds are protected within a fruit
                                   B. Life cycle of Seed Plants
Show alternation of generations. The sporophyte generation is the plant that is most visible. The
              gametophyte is very tiny, growing and maturing within the structure of the
              sporophyte called either a flower or a cone. This adaptation eliminates the need
              for standing water in the reproductive process.

Competency 0019

Characteristics, functions and adaptations of animals

1. Contrast and compare life cycles of vertebrates and invertebrates




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          Vertebrates – Backbone                     Invertebrates – without a backbone
Phylum: Chordata. Classes: Mammals, birds,        Phyla: Porifera (sponges); Cnidaria (hydra,
reptiles, amphibians, fish                        jellyfish); Platyhelminthes (flatworms, flukes,
                                                  tapeworms); Nematoda (roundworms);
                                                  Mollusks (clams, snails); Annelids
                                                  (earthworms); Arthropods (spiders, insects);
                                                  Echinoderms (sea stars, sea urchins);
                                                  Invertebrate Chordates (tunicate)

    Sexual reproduction                          Sexual and Asexual reproduction techniques.
    Land based                                   Hermaphrodite forms in some species
    Larger size, active lifestyle                Many are marine creatures
    ↑ fuel req, amniotic egg was a               Increasing complexity through the phyla
        reproductive adaptation enabling          Great diversity
        survival on land
    amniotic egg develops in reproductive
        tract of female
    Neural crest, cephalization, vertebral
        column, closed circulatory system



2. Processes of Life: Order (organization – cell, tissue, organs, organ system), growth and
development, energy utilization (feed, respire, internal transport, excretion), response to
environment, homeostasis, movement, reproduction

3. Metabolic rates of animals – amount of energy it takes to maintain each gram of body weight
is inversely related to body size, i.e., the smaller the animal the higher the metabolic rate.

     Metabolism definition – the totality of an organism’s biochemistry

     Harvest chemical energy from food ingested
     Energy measured in calories or kcal



Competency 0026 – sub area I – Ecology

Population– individuals of a single species that simultaneously occupy the same geographic area,
rely on the same resources, are influenced by similar environment and have an ↑ degree of
interacting with others.

Density – the # of individuals per area.

Dispersion – The pattern of spacing among individuals.



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Community – All organisms that inhabit a particular area or the different species that live close
enough together to have potential interaction.

Factors affecting population size and growth rate
     1. Birth rates, death rates
     2. Exponential model of population growth describes an idealized population with
unlimited resources (a theoretical construct because no environment has unlimited resources)
     3. Logistic model of population growth describes the maximum population size (carrying
capacity) that a particular environment with its finite resources can support with no net increase
or decrease over a long period

Population growth curve:

                   COMPARISON OF TWO MODELS OF POPULATION
                                      GROWTH
                    Exponential Model        Logistic Model
                   No limitation on population       Considers ↑ and ↓ density
                   increase
                   No limit on resources             Relative to the carrying capacity
                                                      of the environment
                                                      ↑ density = ↓ resources



Relationships among organisms with population density
    ↑ predation
    competition for limited resources
    stress relative to crowding
    build up of toxins

The result of any of above →↓ growth rate.


Competency 0027 – Key Terms

Ecosystem                                          Productivity
Tropic structure                                   Net primary productivity
Tropic level                                       Biomass
Primary producers                                  Standing crop biomass
Primary consumers                                  Limiting nutrient
Secondary consumers                                Secondary productivity
Tertiary consumers                                 Biomass pyramid
Detritivores                                       Turnover time
Detritus                                           Pyramid of numbers
Denitrification                                    Biogenochemical cycle
Food chain                                         Nitrogen fixation
Food web                                           Ammonification
Production                                         Long-term ecological research (LTER)


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Consumption                                      Biological magnification
Decomposition
Primary productivity                             *Greenhouse effect
Gross primary productivity


Competency 0027

Ecosystems – major communities of organisms – all the organisms in a given area along with
nonliving factors with which they interact: a biological community and its physical
environment: i.e., rainforest terrarium

Biomes – a major type of ecosystem that covers a large geographic region and that is largely
determined by climate, usually classified according to predominant vegetation, and characterized
by organisms adapted to the particular environments.

Trophic level – a level in a food chain.

Trophic structure – the feeding relationship in an ecosystem. Trophic structure determines the
route of energy flow and the pattern of chemical cycling in an ecosystem.

Herbivores – organism that eats plants.

Consumer – organism that eats other organisms.

Producers – organism that uses the energy from sunlight to make organic food molecules from
CO2; and H20 and other inorganic raw materials, i.e, a plant, algae or autotrophic bacteria.

Autotrophs – organism that makes its own food, sustains itself without eating other organisms or
their molecules. Plants, algae and photosynthetic bacteria are examples. An autotroph is a
producer organism.

Heterotrophs – organism that can’t make its own organic food molecules and must obtain them
by consuming other organisms or their organic products, i.e., a consumer or a decomposer in a
food chain.

Biomass – dry weight of organic matter that composes a group of organisms in a particular
habitat, i.e., the mass of the living things that live in a particular habitat


Net Primary Productivity
Secondary Productivity

*Ecosystem –all biotic and abiotic factors living in a community

    Boundaries of ecosystem are not usually discrete.


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      This is the most inclusive level of biological organization.

      Ecosystems involve two processes that cannot be described at lower levels: energy flow
      and chemical cycling.

      Energy flows through ecosystems and matter cycles within them.

Trophic Relationships info systems

Each ecosystem has a trophic structure of feeding relationships that determine the paths of
energy flow and chemical cycling.

(Ecologist divided species in a community or eco system into different trophic levels based on
their main source of nutrition.)

A. Trophic relationships determine an ecosystem’s routes of energy flow and chemical flow.
(See exhibit)
       5 trophic levels
               Primary producers – beginning of the food chain, autotrophs
               Primary consumers – eats producers (plants or algae), an herbivore
               Secondary consumers – eats consumers, carnivores
               Tertiary Consumers – carnivores that eat mainly carnivores
               Detritivores - eats dead organic material, (decomposers)

B.    An ecosystem’s trophic structure determines the routes of energy and chemical cycling.
         Food chain – pathway along which food is transferred from trophic level to trophic
           level
                Rarely are unbranched – several different primary consumers may feed on
                  same plant species and primary consumer may eat several species
                Feeding relationships are woven into elaborate food webs in an ecosystem.

*All organisms carry out each of three system processes to some extent:
        Production – in some sense, all organisms incorporate energy and materials into their
           bodies
        Consumption – all organisms metabolize organic molecules for growth &
           reproduction
        Decomposition – all organisms perform some decomposition, i.e., in cellular
           respiration they break down organic molecules and release inorganic CO2, H2O, and
           NH4+

C. Primary producers are plants, algae and many species of bacteria. The main primary
producers will vary depending on the system
        Plants are the main producers in most terrestrial systems.
        Debris falling from terrestrial plants reach streams – is a major source of organic
          material.


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          Phytoplankton (algae & bacteria) is the most important autotrophs in limnetic zone of
           lakes and in the open ocean
        Multicellular algae and aquatic plants are primary producers in the shallow, near
           shore areas of fresh water and marine ecosystems.
        Chemoautotrophic bacteria utilize energy from the oxidation of hydrogen sulfide in
           the aphotic zone of the deep sea.
D. Many primary and higher order consumers are opportunistic feeders – supplementing their
main diet with what is available: autotroph, heterotroph, or detritus (dead material)

E. Decomposition interconnects all trophic levels
       Organic matter that composes living organisms into ecosystems is eventually
         recycled, decomposed and returned to a biotic environment in a form that can be used
         by autotrophs.
       Bacteria and fungi most important decomposers
       Decomposition links all trophic levels.

F.   Energy flow in ecosystems

     A. An ecosystem’s energy budget depends on primary productivity
        Global energy budget – total incoming solar energy ultimately trapped by
          photosynthesis
        Primary productivity – amount of light energy that is changed to chemical energy by
          autotrophs

Exhibit: Trophic Level

Autotroph – plants – primary producers
Heterotrophs – consumers

     A. Examples of trophic level:

       1. Terrestrial food chain

              Insect gets pollen → mouse eats insect → snake
              eats mouse → hawk eats snake

              flower → herbivore → carnivore → carnivore → carnivore

       2. Marine food chain

              phytoplankton → eaten by zooplankton → little fish eats zooplankton
              (carnivore) → large fish eats little fish (carnivore) → whale eats big fish
              (carnivore)


     B. As energy flows through an ecosystem, much is lost at each trophic level.



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       1. Secondary productivity
       2. Ecological efficiency and ecological pyramids.
                  Ecological efficiency – percentage of energy transferred from one trophic
                      level to the next (varies greatly among organisms from 5%-20%)

III. Cycling of chemical elements in ecosystems.

    A. Biological and geological processes move nutrients among organic and nonorganic
compartments. (See illustrations provided)

       1.   Water cycle
       2.   Carbon cycle
       3.   Nitrogen cycle
       4.   Phosphorus cycle

     B. Decomposition rates largely determine the rates of nutrient cycling.

     C. Field experiments reveal non-vegetation regulates chemical cycling.
         Research shows that the amount of nutrients leaving an intact forest ecosystem is
            controlled by plants themselves. Removal of vegetation causes Ca2+ to be lost to
            streams which carry it out of the ecosystem

IV. Human impacts on ecosystems

     A. The human population is disrupting chemical cycles throughout the biosphere.

              Agricultural effects on nutrient cycling.
              Accelerating eutrophication of lakes from sewage, factory waste, animal waste
               from pastures, stockyards, fertilizers, etc.

               o Toxins from chlorinated hydrocarbons, pesticides, PCBs, etc. can become
                 concentrated in successive levels of food webs.

               o Human activities are causing fundamental changes in the composition of the
                 atmosphere.

                      Carbon dioxide emissions from combustion of fossil fuels and
                       deforestation burning contributes to the greenhouse effect (the retention of
                       solar heat causing global warming)

                      Depletion of ozone which absorbs ultraviolet radiation due to refrigerants,
                       aerosol propellants, and manufacturing processes

Competency 0028

I.   Water cycle – role of bacteria in nutrient in ecosystems


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       Precipitation – release of moisture in the air; globally, precipitation exceeds evaporation
          over land. Runoff flows back to sea through surface and ground water systems
       Evaporation – loss of heat from the surface of a liquid – globally, evaporation exceeds
          precipitation over oceans which causes movement of water vapor from oceans to land
       Transpiration – loss of water from a plant by evaporation accounts for 90% of the water
          vapor over land
       Percolation – seeping of water into the soil from precipitation
       Vapor transport – vapor in the air. Moves from ocean toward land
       Groundwater flow – results from precipitation flows to underground flow – precipitation
          over land ultimately flows to sea via runoff and ground water

II.     Nitrogen cycle
       Nitrogen is available to plants in two forms:
               o Ammonium (NH4+)
               o Nitrates (NO3-)
       Nitrites NO2- -
       N2 – Atmosphere is 80% nitrogen gas, which is unavailable to plants

       Assimilation – ability to utilize a substance such as nitrogen for metabolism. Animals can
          only assimilate organic nitrogen by eating plant or other animal proteins
       Nitrification – process by which some aerobic bacteria use ammonium in soil as energy
          source and oxidize NH4+ to NO2- (nitrite) and then to NO3- (nitrate), which is assimilated
          by plants
       Ammonification – decomposition of organic nitrogen (amino acids and proteins) back to
          ammonium ion (NH4+) by bacteria and fungi
       Denitrification – process by which some bacteria can utilize oxygen available in nitrates
          (NO3-) under aerobic conditions. This process returns N2 to the atmosphere
       Nitrogen gas (nitrogen cycle) - Atmosphere is 80% nitrogen gas, which is unavailable to
          plants

III     Carbon Cycle:
       Photosynthesis – process by which plants use energy to produce carbohydrates
       Primary consumer – animals that eat plants, herbivores
       Higher-level consumer – animals that eat other animals, omnivores and carnivores
       Detritvores – living things that utilize dead organic material as food/energy source
       Detritus – non-living organic material, dead stuff
       Burning – returns CO2 to the atmosphere
       Cellular respiration – utilization of organic molecules as an energy source, requires O2,
          most efficient process for production of ATP (energy carrying molecule used by cells to
          carry on life processes
       Notes:
       Less light – less organic material produced less chemical energy available to consumer .
       Too much CO2 greenhouse effect.

      III.   Human Impact



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    Disruption of Chemical Cycles by Human Activity
    Greenhouse Effect
    Biological Magnification – a variety of toxic chemicals cannot be degraded by
       microorganisms; therefore, remaining in the environment for years. Ingestion may cause
       endocrine system disruption in large number of animal species, including humans.
    Changes in Atmosphere due to Human Activities – depletion of atmospheric ozone leads to
       increased nitrogen oxides contributing to atmospheric warming and acid precipitation.
    Human population explosion alters habitats and reduces biodiversity

Competency 0029


Scope of ecology
Study between organisms and their environment
Adaptation of organisms to ecosystems
Evaluating environmental issues

Abiotic vs. Biotic Factors of an Environment
    Abiotic – the climate, the nonliving chemical and physical features of a specific
       environment – temperature, water availability and quality, nutrients, etc.
    Biotic – living organisms of a specific environment; the individual organisms, and the total
       physiological, morphological and behavioral characteristics of those organisms
    Organismal ecology is response to above
    Climate and abiotic factors are important determinants of the biosphere’s distribution of
       organisms
   
       Bio waste
       Biochemical – warfare


Communities – all species living in proximity       Population Dynamics are based upon the needs
allowing for interaction among them                 of the species for energy, mutations that occur,
(all fish, turtles, amphibians, insects, plants and and adaptation (change over time)
other living things living in a stream)

Population– group of individuals of the same
species living in a particular area
(all trout in the stream)

Organism – a single individual; one member of
a species
(a single trout)




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                                             Resources

Resource of ecosystems affect humans
Over world view (i.e., preserving national parks)

Matter

Energy – helio (?) electric fossil fuel

Key Terms:

Ecology, population, community, ecosystem, climate
Principle of allocation, tolerance limits, biomes, dessert, forest, biosphere, zones (earth w/temp),
cosmic catastrophe (periodic disturbances [energy]) Prediction of impact on ecosystem.

    Principle of Allocation – each organism has limited amount of energy that can be allocated
       for obtaining food, escaping predators, coming with environmental fluctuations
       (maintaining homeostasis) growth and reproduction.
           o Energy an organism uses for homeostasis is not available for other purposes
           o Different priorities in energy allocation are related to distribution and homeostatic
               mechanisms
    Tolerance Limits – range of environmental change within which an organism can adjust its
       energy allocation
    Acclimation – slow process that involves trade offs allowing physiological adjustment to
       environmental change – substantial but reversible changes that shifts an organisms
       tolerance curve in the direction of an environmental change.

Alg. Ryth. (?)

Biosphere – entirety of Earth that is inhabited by the sum total of all the planet’s communities
and ecosystems

Biomes:

Aquatic Zones:         occupy the largest part of biosphere
                                   o Oceans occupy 75% of the Earth’s surface
                                            o Zones: Intertidal, Neritic, Oceanic Zone
                                   o Freshwater Biomes:
                                            o Swamps, Marshes, Estuaries
                       ↑ photic – sufficient light to support photosynthetic plankton
                       ↓ aphotic – little light penetrates to this level; insufficient for
                          photosynthesis

    Thermo cline – layer of water with unstable temperature between upper layer of warm water
       and lower layer of uniformly cold deeper water.




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    Benthic zone – (ooze on floor of body of H2O) – the bottom of an aquatic body. Organisms
       survive on detritus that settles to the bottom of the body of water.

    Benthos – communities of organisms living on the bottom of a body of water
    Detritus – dead organic matter; source of energy and nutrients for benthos

Terrestial Biomes – based mainly on regional variations in climate
    Tropical Rainforest
    Savanna – Grasslands
    Deserts –dry
    Chaparral – dry scrub land – winters mild and rainy; summers hot and dry
    Temperate Grasslands – drought, deep rich soil, forest fires
    Temperate Forests – mid-latitudes with sufficient moisture to support large, deciduous trees
    Coniferous Forests
            o Coastal – temperate rainforests
            o Taiga – northern coniferous forests (long, cold, snowy winter; short summer)
    Arctic Tundra – cold temperatures, windy, permafrost
            o Limits plant growth to shrubby or mat-like growth
            o Alpine tundra at high altitudes


Competency 0027

Compare the strengths and limitations of various pyramid models. Pyramid of productivity:
diagrammatic representation of loss of energy from a food chain.

Primary productivity – rate at which organisms synthesize new biomass

I. Biomass pyramid – each tier represents standing crop biomass (total dry weight of all
organisms) in a trophic level

      A. Strengh(s)
      B. Weakness(es)
        1) Some producers have a low standing crop biomass compared to their productivity;
i.e., some aquatic ecosystems have an inverted biomass pyramid with consumers outmassing
producers because the producers (phytoplankton) reproduce rapidly and are also consumed at a
high rate (but their productivity pyramid is upright because the phytoplankton have a higher
productivity than zooplankton)

II. Numbers pyramid – size of each block is proportional to the number of individual organisms
present in each trophic level.

     A. Strength(s)

     B. Weakness(es)




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The overall biomass of top level carnivores is limited because of the multiplicative loss of energy
up the pyramid. Top level predators are large, limited biomass is concentrated in a small number
of individuals (thus live widely spaced- competition for food leaves these predators susceptible
to extinction)

III. Energy pyramid – (AKA pyramid of productivity)

     A. Represents the cumulative loss of energy from food chain from the base to the apex

80%-95% of energy at one trophic level never transfers to the next trophic level. The pyramid is
bottom heavy because ecological efficiencies are low.



Phenotype – the physical and physiological traits of an organism.

Hybrid vigor – crossbreeding between two different inbred varieties often produces hybrids that
are much more vigorous than either parent stock. This hybrid vigor is probably due to:
     1. Segregation of harmful recessives that were homozygoms in the inbred varieties.
     2. The heterozygote advantage at many loci is the hybrids.

Genotype – the specific genes for a trait that an organism has.




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