bio chapters 13-15 & 17exam 3

  1. What are the two main concepts of Darwin's 'on the origin of natural species by means of natural selection' book?
    • 1. Life evolves
    • 2. Change occurs as a result of decent with modification with natural selection as the mechanism.
  2. What is natural selection?
    The processs in which organisms with certain inherited characteristics are more likely to survive and reprodce than individuals with other characteristics.
  3. What drives evolution?
  4. Natural selection leads to ____ changing over generations.
    populations: a group of individuals of the same species living in the same place at the same time.
  5. Aristotle believed....
    that species are fixed and do not evolve over time.
  6. Georges Buffon noted that, in regards to evolution;
    The earth may in fact be over 6,000 years old and there are similarities between fossils and living species, and fossil forms might be ancient versions of similar living species.
  7. What did Lamarck's theory of evolution stated:
    • Enviornments give risse to changes in animals. Acquired characteristics could actually be interited! And organisms evolved by the process of adaption during their lifetimes and these characteristics could be inherited. i.e; the giraffes....
    • This theory is now known to be incorrect...duh.
  8. Who was charles Lyell?
    The geologist that greatly influenced Darwin. Lyell said that the earth is very old and the planet has been sculpted b by gradual geological processes that are continuing today.
  9. What are some examples pf evidence in support of evolution?
    • 1. The fossil record.
    • 2. Biogeography.
    • 3. Comparative anatomy.
    • 4. Comparitive embryology.
    • 5. Molecular biology.
  10. What is an exmple of a fossil record that is supportative to the theory of evolution?
    the grand canyon...fossils reveal the appearrance of organisms in a historical sequence.!
  11. What is biogeography?
    The study of geographic distribution of species. The first field suggested to Darwin that today's organisms evolved from ancestral forms. ie; marsupials in australia!
  12. what is comparative anatomy?
  13. • comparison of body structure between different species confirms that evolution is a remodeling process
    • • Homology is the similarity in structures due to common ancestry
    • • Illustrated by the remodeling of the pattern of bones forming the forelimbs of mammals
  14. what is comparative embryology?
  15. Early stages of development in different animal species reveal additional homologous relationships.
    • • Comparative embryology of vertebrates supports evolutionary theory.
    • Example: pharyngeal pouches appear on the side of an embryo’s throat, which:
    • • Develop into gill structures in fish
    • • Form parts of the ear and throat in humans
  16. What were Darwins two key observations that lead to his theory of Natural Selection?
    1. All species tend to produce excessive numbers Æ leads to a struggle for existence.

    • 2.
    • • Variation exists among individuals in a population.
    • • Much of this variation is heritable.
  17. what us a population?
  18. • A group of individuals of the same species, living in the same place, at the same time
    • The smallest biological unit that can evolve
  19. Gene pool:
  20. The total collection of alleles in a population at any one time
  21. what is microevolution?
  22. • When the relative frequency of alleles changes over a number of generations, evolution is occurring on its
    smallest scale,
  23. what does polygenic mean in relation to variable traits in a population?
    polygenic results from the combination of several genes.
  24. single gene traits...
  25. tend to produce phenotypes that vary more or less continuously.
    • • Determined by a single gene
    • • Single gene traits tend to produce only a few distinct phenotypes.
  26. what is the hardy-weinberg formula?
  27. p=...
    the relative freguency of the dominant sllele in the population.
  28. q=
    the frequency of the recessive allele in the population
  29. what is the hardy weinberg formula used for?
    To determine the frequencies of genotypes in a gene pool from the frequencies of alleles. This formula may be used to calculate the percentage of a human population that carries the allel for a particulaar inherited disease.
  30. How can we tell a population is evolving?
  31. • A non‐evolving population is in genetic equilibrium with the population gene pool constant over time Æ
    • Hardy‐Weinberg equilibrium
    • • evolution can be defined as a generation‐to‐generation change in a population’s frequencies of alleles Æ
    • Microevolution
  32. Genetic drift:
    • A change in the gene pool of a small population, due to chance

    • • results from a drastic reduction in population size
    • • usually reduces genetic variation because at least some alleles are likely to be lost from the gene
    • pool.
  33. What is the founder effect?
  34. • likely when a few individuals colonize an isolated habitat and represent genetic drift in a new
    • colony.
    • • explains the relatively high frequency of certain inherited disorders among some small human
    • populations.
  35. What is gene flow?
  36. • genetic exchange with another population
    • tends to reduce genetic differences between populations
  37. What is Darwinian fitness?
  38. • Of all causes of microevolution, only natural selection promotes adaptation.
    • • Fitness is the contribution an individual makes to the gene pool of the next generation relative to
    • the contributions of other individuals.
    • Example: fitness of some flowering plants depends in part on competition in attracting pollinators
  39. What are teh three general outcomes of natural selection?
    • 1. Directional Selection.
    • 2. Disruptive selection.
    • 3. Stabalizing selection.
  40. What directional selection?
  41. • Shifts the phenotypic “curve” of a population
    • Selects in favor of some extreme phenotype
  42. What is disruptive selection??
  43. • can lead to a balance between two or more contrasting phenotypic forms in a population.
  44. What is stabalizing selection?
  45. • Favors intermediate phenotypes and is the most common
  46. What is sexual selection?
  47. • a form of natural selection in which inherited characteristics determine mating preferences.
  48. What is sexual dimorphism?
    A distinction in appearance between males and females and is not directly associated with reproduction or survival.
  49. Systematics focuses on:
    • • Classifying organisms
    • • Determining their evolutionary relationships
  50. What is taxonomy?
    • • Naming of species
    • • Classification of species
    • • Identification of species
  51. What is a biological species?
  52. A group of populations whose members have the potential to interbreed and produce
    • fertile offspring
    • • cannot be accurately used with Fossils or Asexual organisms
  53. binomial....
    A name that is given to all living organisms that is a two part name consisting of a genus and a species.
  54. What is the taxonomic heirarchy?
    • Species
    • Genus
    • • Family
    • • Order
    • • Class
    • • Phylum
    • • Kingdom
    • • Domain
  55. Who divided all known forms of life between 2 kingdoms (plant or animal)?
  56. Linnaeus (1700s):
  57. Who proposed a five‐kingdom system that placed all prokaryotes in one kingdom & Divided the eukaryotes among four other kingdoms?
  58. Whittaker (1950s)
  59. Woese (1970s) molecular studies and cladistics led to development of a three‐domain system, what is this system ??
  60. • Two domains of prokaryotes (Bacteria and Archaea)
    • • One domain of eukaryotes (Eukarya)
    • • Three‐domain classification system (see Figure 14.25)
  61. Earth was formed about....
    4.6 billion years ago.
  62. 3.5 billion years ago what happened?
  63. Prokaryotes lived and evolved...
    • Prokaryotes lived and evolved on earth about 2 million years before any eukaryotes lived and.or evolved.
    • They can cause disease but also be beneficial.
  64. What is the structure and function of prokaryotes?
    Prokaryotes lack true nuclei, they lack other membrane-bound organelles and have cell walls exterior to their plasma membranes.
  65. What are the three shapes that prokartyotes may come in?
    • Spherical (cocci), Rod-shaped (bacilli) or spiral
    • Usually prokaryotes are very small., some form true colonies like an actinomycete and some show specialization of cells and some are very large.
  66. what are the 4 major modes of nutrition for prokaryotes?
    • 1. Phototrophs
    • 2. Chemotrophs
    • 3. Autotrophs
    • 4. Heterotrophs
  67. phototrophs:
    Energy source comes from light.
  68. chemotrophs:
    energy comes from enviornmental chemicals.
  69. autotrophs:
    carbon from carbon dioxide
  70. heterotrophs:
    obtain carbon from at least one organic nutrient (glucose)
  71. What are the two major branches of prokaryotic evolution?
    • 1. Bacteria
    • 2. Archaea
  72. Pathogens:
    Bacteria and other organisms that cause disease.
  73. exotoxin:
    poisonous proteins secreted by bacterial cells.
  74. endotoxins:
    chemical components of the outer membrane of certain bacteria.
  75. Protists:
    Ancestral to all other eukaryotic organisms like plants, fungi and animals. and they probavblty evolved from prokaryotic ancestors.
  76. Where did eukaryotic cells come from ?
    One theory is the ENDOSYMBIOTIC THEORY, which states tthat the infolding of the plasma membrane of a prokaryotic cell actually formed the endomembrane system (the endoplasmit reticulum, etc). ENDOSYMBIOSIS produced mitochondria and chloroplasts and free-living bacteria came to reside inside of a host cell.
  77. Protists are not one groupn, instead they represent.......?
    all the eukaryoites that are not plants, animals, or fungi.
  78. What are the four major categories of protists?
    • 1. Protozoans (first animals)
    • 2. slime molds
    • 3. unicellular and colonial algae
    • 4. green algae
  79. Protozoans:
    • one of the categories of protists!
    • They live primarily by
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bio chapters 13-15 & 17exam 3
bio exam 3