bio main concepts

• proteome


  the entire set of proteins expressed by a given cell or group of cells
• gene density


  number of genes in a given length of DNA
• repetitive DNA


  makes up much of the DNA
• transposons


  replicated DNA inserted in another portion of our genome
• retrotransposons


  moves via an RNA intermediate
• novel functions can evolve by

  extra sets can diverge by accumulating mutations
• transposable elements


  can provide sites for crossover between nonsister chromatids
• homeotic genes


  important in controlling the pattern formation of body parts
• Lamarck's hypothesis


  species evolve through use and disuse of body parts and the inheritance of acquired characteristics
• descent with modification by natural selection explains

  adaptations of organisms and the unity & diversity of life
• natural selection


  favorable inherited traits are more likely to survive and reproduce
• adaptive radiation


  species evolves into many new species to fill all the unfilled niches
• Darwin's three observations


  unity of life

  diversity of life

  ways organisms are suited to live in their environments
• homologous structures


  variations on a structural theme present in a common ancestor
• natural selection can only act on

  variation with a genetic component; already present
• harmful mutations


  can be hidden from selection in recessive alleles
• Hardy-Weinberg equation can be used to test

  whether a population is evolving
• conditions for Hardy-Weinberg


  no mutations

  random mating

  no natural selection

  extremely large population size

  no gene flow
• genetic drift


  random change in allele frequencies that occurs in small populations
• bottleneck effect


  drastic reduction in population size
• gene flow


  movement of alleles among populations
• natural selection is the only mechanism that

  consistently causes adaptive radiation
• speciation


  one species splits into two or more
• habitat isolation


  populations live in different habitats and do not meet
• temporal isolation


  species breed at different times of day or different seasons
• behavioral isolation


  courtship rituals and other behvaiors unique to a species
• mechanical isolation


  morphological differences prevent fertilization
• gametic isolation


  sperm of one species may not be able to fertilize eggs of another species
• reduced hybrid viability


  genes of the different parent species may interact and impair the hybrid's development or survival in its environment
• reduced hybrid fertility


  even if hybrids are vigorous, they may be sterile
• hybrid breakdown


  offspring of the next generation are sterile
• biological species concept emphasizes

  absence of gene flow
• morphological species concept


  defined by structures
• ecological species concept


  based on location
• phylogenetic species concept


  smalled group on the phylogenetic tree
• allopatric speciation


  gene flow is interrupted because population is divided into geographically isolated populations
• sympatric speciation


  same geographic area; can occur if gene flow is recued by factors including: polyploidy, sexual selection, habitat differentiation
• polyploidy


  extra sets of chromosomes due to accidents during cell division
• allopolyploid


  species with multiple sets of chromosomes derived from different species
• conditions on early earth that made the origin of life possible


  abiotic synthesis of organic molecules

  macromolecules

  protocells

  origin of self-replicating molecules