The following information is provided to help you study for the third sectional exam.  Part A & B (terminology & concepts) represent "core" material that all Bio 120 instructors are expected to cover in their class.  The "standardized" portion of the final exam could contain questions about any of this material. Part C (classroom discussions, etc.) represents material that has been covered in class beyond the "core" material.  It is material that I will ask about on our sectional exam.  

A] Terminology:

• Genome - complete genetic information of an organism or species
• PCR - (Polymerase Chain Reaction) a method to rapidly copy specific DNA fragments
• Genetic engineering - changing the genetic makeup of an organism, often with the intent to alter its phenotype. A gene may be transferred between species or modified and reinserted into an organism of the same species.
• Transgenic - refers to an organism into which DNA from another species has been inserted
• DNA Sequencing - method of determining the linear sequence of nucleotides in DNA
• Gel electrophoresis - the sorting of DNA fragments by size in an electric field
• DNA Fingerprinting - a technology that answers identity questions concerning individual organisms by looking at DNA fragments that have been sorted by the size of the fragments
• Human genome project - large international research project whose goal is to sequence and map all the genetic information found in humans
• Gene therapy - transfer of normal or modified genes, often with the intent to correct a genetic defect
• Eugenics - genetics used to "better" the human race by getting rid of undesirable traits
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• Evolution - change over time
• Biogeography - the study of patterns in the geographic distribution of species and communities
• Fossils - traces or remains of living things from a previous geologic time
• Comparative morphology - the comparison of body structures in different species
• Natural selection - nature determines which organisms will survive and reproduce based on the unique inherited variations that the organism possesses; the major driving force of evolution
• Molecular biology - the study of molecular basis of genes and gene expression; used in evolutionary studies when DNA is compared between different species
• Adaptation - a heritable aspect of form, function, behavior or development that improves the odds for surviving and reproducing in a given environment
• Gene pool - all the genetic resources available within a population
• Directional selection - selection for an extreme phenotype
• Stabilizing selection - selection for an central average phenotype
• Disruptive selection - selection for both extremes of phenotype and selection against the central average phenotype
• Non-random mating (sexual selection) - evolution due to preference of one sexual partner for certain attributes in the other sexual partner
• Genetic drift - evolution that is driven by chance events alone
• Gene flow - evolution (or the lack of evolution) due to amounts of immigration and emigration between different populations
• Mutation - a change in the nucleotide sequence of DNA
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• Radiometric dating - a method for determining the age of fossils or rocks by looking at proportions of radioisotopes and their decay products in a given sample
• Geological time scale - a chronology of Earth's history separated into time periods based on major events associated with living things
• Plate tectonics - the forces that move the crustal plates of the planet
• Continental drift - the idea that all land on Earth was once one great mass, which broke up into continents that drifted to their present positions
• Comparative morphology - the comparison of body structures in different species
• Homologous structures - structures that are of the same evolutionary origin, with the same basic anatomy, but which may or may not differ in function
• Analogous structures - similar structures that evolve within organisms that have developed from different ancestors; they have a similar function but have different basic anatomies and evolutionary origins
• Species (biological species concept) - a population or group of populations that interbreed freely in the wild and does not interbreed with other populations and which can produce fertile offspring
• Speciation - the process by which new species are formed during the process of evolution
• Genetic divergence - the development of separate gene pools in populations that have been separated from one another
• Reproductive isolation mechanisms - mechanisms which prevent different species from mating and having fertile offspring with one another
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• Ecology - the study of the interactions between living things and other living things and their physical environment
• Population - a group of interacting individuals of the same species that inhabit a defined geographical area
• Demographics - 
• Exponential growth - population growth model of the rate of expansion of a population under ideal conditions; the population multiplies by a constant factor during constant time intervals
• Carrying capacity - the number of individuals in a population that the environment can just maintain with no net increase or decrease
• Logistic growth - population growth model of an ideal population whose growth is slowed by limiting factors
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• Community - consists of two or more populations of different species occupying the same geographical area (or, all the living things in a given area)
• Habitat - the actual area or home where a living thing resides
• Niche - an organism's uise of the biotic and abiotic resources in its environment and its special role within an ecosystem
• Mutualism - a type of symbioses where two species live together in close association, both benefiting from the relationship
• Predation - a relationship in which members of one species eats members of another species
• Parasitism - a type of symbioses where an organism of one species benefits from its interactions with another, whereas the other species is harmed
• Symbiosis - a close relationship between two different species
• Coevolution - process where two different species evolve in response to changes in the other
• Competitive exclusion principle - if two species are competing with one another for the same limited resource, the species able to use that resource most efficiently will eventually eliminate the other species in that location
• Predator - the organism that eats other organisms
• Prey - the organism that is fed upon
• Mimicry - evolutionary process which leads to similarity in body form and color in two or more species that are not closely related 
• Ecological succession - process of community change which occurs in an area after disturbance
• Primary succession - process by which life moves into an area for the first time
• Secondary succession - occurs when an existing community is altered by a natural or man-made disturbance
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• Ecosystem - consists of a community of living things interacting with the physical factors of their environment
• Primary producers - organisms that can make their own food
• Consumers  - organisms that eat other organisms or their waste products for food
• Trophic level - feeding levels within an ecosystem
• Food chain - series of organisms in different trophic levels which feed upon one another
• Food web - the interconnected and interwoven feeding relationships between organisms in an ecosystem
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B] CONCEPTS:

• Pieces of DNA can be isolated and mass produced by a technique called polymerase chain reaction (PCR)
• Gel electrophoresis – a technique that allows the separation of DNA fragments based on the size of the fragments
1. DNA fragment moves through a gel due to an electric current
2. DNA has a slight negative charge (remember: opposites attract & same charges repel)
• DNA fingerprints
1. Reveals differences in the tandem repeats among individuals
2. PCR can be used to make many copies of the tandem repeat areas of the DNA
• Human genome project
1. Sequencing (finding the exact order of CGAT nucleotides) of human DNA
2. About 21,000 genes have been identified for humans (although we are not sure what proteins all those genes code for)
3. Mapping of chromosomes (what genes occur where)
4. Comparing genes of humans with other organisms
5. Potential for gene therapy
• Ethical considerations involved with genetic engineering of humans
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• Jean Lamarck and evolution of living organisms through acquired characteristics
• Charles Lyell – geologist who stated that the Earth was much older than previously thought, that change occurred gradually over long periods of time, and that the same forces involved with change at present worked the same way in the past and will work the same way in the future
• Charles Darwin provides the idea of “descent with modification” and the mechanism that causes change over time – natural selection (he published his ideas in the book: On the Origin of Species)
• Natural selection
  • Observation – organisms produce many more offspring than can survive
  • Observation – organisms show variation in their structures and behaviors that are inherited
  • Conclusion – Nature decides which variations are the best for survival and reproduction.  Those with the “best” variations will survive and reproduce while those with less desirable variations will die and their undesirable variations will not be passed on to the next generation
  • Remember – passing variations (genes or alleles) forward in time (reproductive success) is the key for being evolutionarily successful!
• Mutations function as the raw material for evolutionary change
• Other important mechanisms that lead to biological evolution: (see definitions in Part A for descriptions of these processes)
  • Genetic drift
  • Gene flow
  • Mutation
  • Non-random mating
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• Evidence of evolution – comes from biogeography, fossils, comparisons of body form, development, biochemistry, and DNA among/between different groups
• How new species evolve – disruption of gene flow, genetic divergence, speciation and the development of reproductive isolation
  • One species becomes two when a group of individuals becomes reproductively isolated from the rest of the species
  • Prezygotic and postzygotic reproductive isolation mechanisms
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• Origin of life – experiments show that organic molecules that serve as the building blocks of life can form spontaneously, as can cell-like structures (first steps toward the origin of life)
  • What the Earth was like when life first formed
  • Stanley Miller’s experiment on forming complex organic molecules from simple inorganic molecules
  • Prokaryotic life was the first type of life on the planet
  • Photosynthesis and the addition of oxygen to the Earth’s atmosphere
  • The oxygen enriched atmosphere put an end to the further spontaneous chemical origin of life
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• During a specified interval, population size is an outcome of births, deaths, immigration and emigration
• With exponential growth, population size increases by a fixed percentage of the whole in each interval
  • Its reproductive base gets larger and larger over time
  • A graph of population size against time produces a J-shaped growth curve
  • This type of growth cannot continue indefinitely – sooner or later required resources for life are used up and the population will crash
• Resources in short supply put limits on population growth
• With logistic growth, population size increases until the carrying capacity of the environment is reached
  • A graph of population size against time produces an S-shaped growth curve
  • Carrying capacity may change in an environment as resource availability changes
• The world’s human population has surpassed 6.4 billion
  • Through expansion into new habitats, cultural intervention and technological innovation, the human population has temporarily skirted environmental resistance to growth
  • Human growth curve (see Fig. 18.12)
  • Birth rates fall as nations become more industrialized, but their per capita consumption of resources increases.
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• The structure of a community is determined by physical factors and by the interactions among species within it.
• Close interactions between species can lead to coevolution
• Competition has negative effects on both participants
• Species that have dissimilar resource requirements are more likely to coexist than those having similar needs
• Predators and prey exert selective pressure on one another
• By the process of ecological succession, one array of species replaces another in a sequential fashion
  • Primary succession occurs in habitats more or less devoid of life
  • Secondary succession occurs in areas where an existing community has been severely disturbed
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• In an ecosystem energy flows in one way through organisms while nutrients are cycled among organisms
• An organism’s trophic level describes how many steps it is from the ecosystem’s energy source
• With each energy transfer, some of the energy is lost as heat.  These losses limit the number of trophic levels in ecosystems
• Ecologists measure the amount of energy and nutrients that enter an ecosystem, the amounts captured, and the proportions stored in each trophic level
• Atmospheric concentrations of greenhouse gases trap heat and keep Earth warm enough for life

1. When are genetic diseases most likely to be cured by gene therapy?
2. Applications of DNA fingerprints (e.g. gauge the success of bone marrow transplants; reunite families; monitor breeding patterns of endangered species; identify the dead; etc.)
3. Artificial selection - people determine which organisms will survive and reproduce based on desired variations that an organism possesses

4. The "Big Bang"

   • Edwin Hubble - movement of galaxies & expanding universe

   • Big Bang - approximately 13-15 billion years ago (be able to briefly describe this theory!)

5. What the Earth was like when life began

   • formation of our solar system & sun - approx. 4.6 billion years ago

   • first evidence of life at 3.8 billion years ago

   • comparison of Earth's atmosphere with other planets in the solar system

   • the primordial (beginning) atmosphere - similar to volcanic gasses with no molecular oxygen

6. Stanley Miller & Harold Urey's experiments

   • results of their experiments

   • results of subsequent experiments by other researchers

   • possible association of the development of life and hydrothermal vents

7. Association of plate tectonics with earthquakes, volcanic eruptions, and mountain formation

8. Human population growth

   • history of human population growth

     • 1650 AD (1/2 billion)

     • 1800 (1 billion)

     • 1930 (2 billion)

     • 1970 (4 billion)

     • 2000 (6+ billion)

   • current trends

     • average population growth in developing countries is much higher than in developed countries

     • no single answer to carrying capacity of Earth for humans - depends on the quality of life that people desire and are willing to accept

     • most estimates suggest that the human population will reach between 10-16 billion before stabilizing

     • most estimates suggest that human populations will reach this level in the next 50-100 years

   • possible solutions

     • increase age of first childbearing

     • increase age before marriage

     • increase education and work opportunities for women

     • make birth control and sex education available to women

   • choice of population control methods involves social, moral, and religious beliefs - difficult to generalize for all populations

9. Climax community - a stable, characteristic community of a geographical area that is the end point of ecological succession
10. Decomposers - a special group of consumers that obtain their nourishment from dead matter
11. Energy pyramid - diagrammatic depiction of energy flow through an ecosystem