bio test 3 101

  1. ecology
    is the branch of ecology that studies how organisms interact with their world
  2. carrying capacity
    The largest population an environment can support
  3. biotic vs abiotic
    biotic-interactions with other organisms, such as predators or competitors

    abiotic-aspects of environment, such as temperature or rainfall, that influence where an organism lives due to its body physiology
  4. life history
    • is the growth and maturity of reprodction how long, elephants are slower, while spiders grow mature and die quicker
    • type 1-low birth but high survival
    • type 2-uniform suvival rate across ages
    • type 3-high birth rate lower survival
  5. community
    all the organisms that share an environment
  6. mutualism/
    when two interacting species both benefit from their exchange
  7. symbiotic
    a close physical association between species
  8. commensal
    When one species benefits from an interaction while the other is indifferent, their relationship
  9. primary-herbivores
    secondary-eat the herbivores
    tericiary-eat carnivores
    decomposers -eat the dead, freeing up nutrients into the soil or water for producers to use
    4 different types of consumers
  10. consumers
    have to get food source from other than the air and sun 4 different types
  11. producers
    autotrophs that fix CO2 into sugars and organic molecules. They are the base of any food chain
  12. keystone species
    species are especially important for keeping balance in their ecosystem! like
  13. ecological succession secondary
    changing of ecosytem that occurs from distrubances like fire
  14. ecological succession primary
    changing of a ecosysten that happens naturally through other things
  15. Bioaccumulation
    • Plants and bacteria pick up small amounts of environmental pollutants and contaminants
    • this is from eating, secondary terciary and decomposers accumulate the most
  16. carbon cycle
    • Atmospheric CO2 dissolves into the ocean and turns into carbonic acid
    • Atmospheric CO2 is taken up (fixed) by photosynthetic plants and bacteria

    Some of this CO2 is released back into the atmosphere by oxidative respiration by the plants, their herbivores, or their decomposer
  17. Water cycles
    water evaporates from the ocean, condenses into clouds, precipitates into rain, runs off into rivers and infiltrates into ground water
  18. Deforestation
    the clearing of forests for timber or farming
  19. Eutrophication
    Increased run-off from farms brings more nutrients (especially nitrogen and phosphorus) into lakes and ocean habitats
  20. Invasive species
    accident or on purpose, introduce plants and animals to new parts of the world
  21. Greenhouse Effect
    Carbon dioxide and Methane are very good at trapping heat in the atmosphere
  22. Gene
    discrete units of genetic (hereditary) information consisting of a specific nucleotide sequence in DNA
  23. allele
    alternate versions of genes
  24. recessive
    The other allele has no noticeable effect on the organism’s appearance and is called the
  25. homologous chromosomes
    chromosomes (giant DNA molecules) which share the same genes. You get one copy of each from your mother, and one from your father
  26. dominant/
    If the 2 alleles of an inherited pair differ, then one allele will determine the organism’s appearance over the other,
  27. homozygous
    An organism that has 2 identical alleles for a gene
  28. heterozygous
    An organism that has 2 different alleles for a gene
  29. segregation
    • A sperm or egg carries only 1 allele for each inherited character
    • This is because chromosome pairs (separate) during gamete (sex cell) formation, aka meiosis
  30. independent assortment
    • The allele pair of one gene separates from each other independently from the alleles of another gene during segregation (meiosis)
    • Ex: segregation of hair color alleles does not influence segregation of ear shape alleles
  31. Dihybrid crosses
    • Examination of 2 separate traits in a single cross
    • ex- XXYY x xxyy
  32. punnet square
  33. carriers
    person or other organism that has inherited a recessive allele for a genetic trait or mutation but does not display that trait or show symptoms of the disease.
  34. genotype
    The complete genetic make-up of an organism
  35. phenotype
    The physical expression of the genotype
  36. test cross
    • how to determine genotype without blood test 
    • ex: test black lab with reccssive brown lab bb, you know black lab is BB if all babies come out black, if half brown it is Bb
  37. incomplete dominance
    • In some allele combinations, dominance does not exist, can result in third trait
    • , the phenotype does reveal the genotype for all traits!
  38. Co-Dominance
    form of dominance in which the alleles of a gene pair in a heterozygote are fully expressed thereby resulting in offspring with a phenotype that is neither dominant nor recessive
  39. Linked Genes
    Genes located close together on the same chromosome tend to be inherited together
  40. Sex-Linked Genes
    A gene located on a sex chromosome is called
  41. Quantitative Traits
    • a measurable phenotype that depends on the cumulative actions of many genes and the environmen
    • ex height weight blood pressure
  42. Pleiotropy
    • Refers to an allele which has more than one effect on the phenotype
    • multiple symtoms  can be traced back to one defective  allele
  43. Epistasis
    the interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another.
  44. Evolution
    _________-is the process of change over time, as applied to organisms.

    Specifically___________is the change in allele frequencies of a population of organisms from one generation to the next
  45. Stabilizing selection
    Extremes of a trait have reduced survival/breeding, keeping a trait stable.

    Most traits are under stabilizing selection
  46. Directional selection
    One extreme of a trait has a survival/breeding advantage. Over generations the population as a whole shifts in that direction.
  47. Disruptive selection
    Selection against the most common phenotype or different selection pressures on different sub-populations.

    May lead to sustained variation or new species!
  48. Frequency-Dependent
    • Fitness of a phenotype depends on its frequency within the population
    • negative type are when the rare thrives
    • positive types are when common thrives, eliminates variation
  49. Hardy Weinberg
    states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.

    • Proportions of genotypes do not change in a population if
    • No mutation takes place
    • No genes are transferred to or from other sources (no immigration or emigration
    • )Random mating is occurring
    • The population size is very large

    No selection occurs
  50. Bottleneck Effect
    happens when a population is drastically reduced at random. The survivors rarely have identical allele frequencies to the original population.
  51. founders effect
    when a small subset of a population starts a new population. The founders rarely have identical allele frequencies to the original population.
  52. genetic drift
    happens when the ‘coin flip’ randomness of sexual reproduction leads to outcomes different than the statistical expectation.
  53. gene flow
    the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies
  54. population
    a group of interbreeding individuals belonging to a particular species sharing a common geographic area
  55. species
    consists of a population whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring, but who cannot successfully interbreed with other groups
  56. Reproductive barrier
    keep individuals of closely-related species from interbreeding
  57. Prezygotic
    keep individuals of closely-related species from interbreeding,is a type of reproductive barrier
  58. Postzygotic
    • genetic mechanisms preventing hybrid organisms (zygotes and beyond) from developing into a reproductively fit adult
    • another reproductive barrier
  59. Allopatric speciation`
    A speciation in which biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the population can no longer interbreed.
  60. Sympatric speciation 
    the process by which new species arise within the range of its predecessor species
  61. Polyploidy
    A cell or an organism having a genome with multiple (more than two) sets of homologous chromosomes
Card Set
bio test 3 101