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Exam 5 - Coggle Diagram

- - - - Each chromosome has partner
      - Homologous chromosomes
        #
      - similar size, shape & hereditary information
      - Each homolog from different parent
      - Interactions of genes on each chromosomes
        
        determines genetic characteristics
    - - During Metaphase I
        
        Orientation of bivalents is random
      - During Metaphase II
        
        Orientation of sister chromatids is random
      - possibilities are 2n
        
        Ex: human with 46 chromosomes
        
        246 = 7.04 x 1013
    - - During Prophase I
      - Synaptonemal complex forms
      - Mixes genes present in homologous chromosomes
      - Results in new combinations
      - Usually at least one chiasma occurs
    - - New combination of alleles from each parent
      - Promotes heterozygosity
      - Advantages
        
        genetic diversity
        
        Bet-hedging to novel environments
        
        Multiple deleterious alleles
        
        can be bunched together and eliminated
        
        Escape host-parasite negative impacts
      - Pollination
        
        Cross pollination vs
        
        Self pollination
  - - - Dominance
      - Segregation
      - Independent Assortment
    - - Each individual has unique genotype
      - Genotype is made of alleles
      - Phenotypes
        
        determined by these alleles
        
        and the environment
      - no guarantee that allele will manifest
        
        Heterozygosity
        
        One of 2 genes
        
        dominant allele
        
        has detectable effect on organism's appearance
        
        other gene has no discernable effect
        
        recessive allele
        
        Homozygosity
        
        both alleles are the same
    - - alleles separated during meiosis
      - Each gamete has one allele for each gene
      - Offspring inherit 2 alleles for gene
        
        One from each parent
        
        homologous chromosome
      - During meiosis
        
        2 members of gene pair separate
      - Each gamete has equal chance to inherit one gene
    - - Punnett square
      - Visual representation of offspring inheritance patterns
      - cross between 2 homozygous parents w/ different alleles
    - - homologs
        
        Gene pairs that are not related segregate
      - Gene pairs not linked segregate independently
      - Evidence provided from a dihybrid cross
        
        3:1 phenotypic ratio for 2 alleles
  - - - Phenotype of heterozygote
        
        intermediate between those parent homozygotes
      - Snapdragons
        
        Red x white = pink
    - - populations > 2 alleles for particular locus
      - Punnett square crossing similar
      - Breeding experiments determine dominance
      - Figuring alleles = complex
    - - Changes in genetic makeup individual
      - Point mutation
        
        Single nucleotide change
      - Chromosome mutation
        
        Deletion
        
        Segments chromosome lost
        
        Duplication
        
        Part of chromosome doubled
        
        Inversion
        
        Piece rotates 180
        
        Translocation
        
        Exchange parts between 2 nonhomologous chromosomes
        
        Transposons
        
        Movable genetic element
        
        Jumping genes
    - - can't mix alleles across homologs
      - Chromosome inherited same as parent
      - Only 2 gamete possible
        
        rather than 4
    - - Multiple genes for one character
      - Phenotype cumulative of combined effects many genes
      - Ex: abscisic acid
      - Most traits
      - Continuous variation
      - Populations have normal distribution
    - - gene interacts w/ another
      - May interfere or mask
      - Ex: digitalis petal color
        
        1 gene impacts red intensity
        
        d light red
        
        D dark red
        
        Pigment location
        
        W spots of nectar guide
        
        w throughout corolla
    - - 4 haploid genotypes
      - Not equal numbers
      - Recombinants less abundant
      - Parentals more abundant
    - - 1 gene w/ multiple effects on phenotype
      - Inheritance of a 1 gene
        
        visibly influences several traits
      - Ex: awn of wheat
        
        w/ awns greater yield than w/out awns
    - - Selfer
        
        Small petals
        
        Flower early
        
        Seasonal drought
        
        Physiologically escape?
      - Outcrosser
        
        flower late
        
        large petals
        
        Seasonal drought
        
        Physiologically tolerant?
    - - 2 copies (2n) of chromosome
      - Autopolyploid
        
        Failed meiosis
        
        Self fertilization
      - Allopolyploid
        
        Meiotic error
        
        Mismatch during mating
        
        Second mating creates matched pairs
      - ex: Wheat
        
        Result of sequential hybrid doubling and quadrupling
        
        Original ancestral species
        
        14 chromosomes
        
        Durum wheat
        
        28 chromosome
        
        Tetraploid
        
        pasta
        
        Bread wheat
        
        42 chromosome
        
        Hexaploid
        
        Gluten for lofty bread
      - ex: strawberry
        
        Chemically induced
        
        Prevent microtubule formation
        
        Required for meiosis to occur properly
        
        Produce diploid gametes
        
        During fertilization
        
        2 diploid gametes fuse
        
        Results in tetraploid (4n)
    - - Polyploid mask deleterious recessive alleles
      - Relax selection pressure
        
        Accumulate mutations
        
        result in beneficial trait
      - 2 groups of ancient duplications
        
        Common ancestor of seed plants
        
        Common ancestor of extant angiosperms
- - - - All alleles of every gene in population
      - population
        
        group of individuals
        
        same species
        
        same region
        
        can interbreed w/ each other
      - Allele frequency
        
        alleles of one type/ total # alleles
      - Genotype frequency
        
        genotypes of one type/ Total # individuals
      - Allele Relative Frequency
        
        of copies of allele in population
        
        Divided by
        
        The total # of alleles for that gene in population
      - genotypic relative frequency
        
        of individuals w/ particular genotype in population
        
        divided by
        
        total # of all individuals in population
    - - if certain conditions exist in population
        
        No new mutations
        
        No genetic drift
        
        No migration
        
        No natural selection
        
        Random mating
    - - p = frequency of dominant allele
      - q = frequency of the recessive allele
      - p+q=1
      - (p+q)2=12
      - p2+2pq+q2=1
        
        p2= genotypic frequency of RR
        
        2pq= genotypic frequency of Rr
        
        q2= genotypic frequency of rr
  - - - Changes in gene pool from gen to gen
      - Factors
        
        Mutation
        
        Change in 1 of nucleic acids
        
        Some apparent in phenotype
        
        Source of new alleles
        
        Must be in gametes to be inherited
        
        Male pollen sperm
        
        Female ovule egg
        
        Natural selection
        
        1 allele selectively advantageous
        
        artificial selection
        
        Selection by humans
        
        Increased frequency of desired trait
        
        Elimination of undesired traits
        
        Crop breeders for thousands of years
        
        Ex: Brassica
        
        Genetic drift
        #
        
        Random loss of alleles
        
        strong in small populations
        
        Bottleneck effect
        
        Large population diminished
        
        Natural catastrophe
        
        Migration # #
        
        Migration
        
        Movement of alleles
        
        into population
        
        Immigration
        
        out of population
        
        Emigration
        
        Can be impeded by
        
        environment
        
        life history
        
        Repercussions for
        
        climate change
        
        GMO
        
        speciation
        
        Nonrandom mating
        
        Plants “choose” their mates
        
        Pollinator vectors
        
        Pollination syndromes
        
        Some reproduce more than others
        
        Based on individual phenotypes
        
        Sexual Selection
        
        Male-male competition
        
        Excess of pollen grains
        
        Pollen tubes can interfere
        
        Female choice
        
        Barriers on stigma surface prevent germination
      - Polymorphism
        
        Dimorphic
        
        2 phenotypes
        
        Dominant-recessive systems
        
        Polymorph = many phenotypes in population
        
        Ex: Aquilegia
        
        Color variation
        
        Spur-length variation
        
        due to a 1 nucleotide polymorphism
    - - Bottleneck from long distance dispersal
      - Followed by adaptive radiation
      - Ex: Hawaiian lobeliads
  - - - Steps summarized
        
        Find Min & Max values
        
        Determine the number of bins
        
        Count # of observations for each bin
        
        Draw bars for each bin w/ frequency
- - - - Population size (N)
      - Exponential growth
        
        J-shaped curve
        
        Unlimited resources
      - Logistic growth
        
        S-shaped curve
        
        Typical of population that
        
        self regulates
        
        Has a carrying capacity (K)
    - - Overshoot K
      - Result in die off
        
        Limited resources
    - - r = intrinsic growth rate
      - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth
        
        dN over dt equals r times N
      - Logistic growth
        
        dN/dt = rN1 - N/K
    - - r-selected
        
        Grow exponentially
        
        Disturbed areas
        
        weedy
        
        annuals
        
        Little investment in defense
        
        Many, small fruits
      - K-selected
        
        Fluctuate around carrying capacity
        
        Fairly stable habitats
        
        Perennials
        
        Invest in defenses
        
        Resource-intensive fruits
    - - Plants must make trade-offs due to environmental necessities
      - Many strategies exist
      - Grime’s model
        
        stress
        
        Resource availability
        
        water
        
        nutrients
        
        light
        
        Growth inhibitors
        
        Temperature
        
        toxins
        
        Disturbance
        
        biotic
        
        Herbivory #
        
        Pathogens
        
        Anthropogenic
        
        Abiotic
        
        fire
        
        wind
  - - - x = age
      - Nx= # of individuals alive at age x
      - Sx=individuals of age x that survive to age x+1
        
        Nx+1/Nx
      - Fx= avg # offspring born to female while she is age x
      - lx= individuals that survive age 0 to age x
        
        Nx/N0
      - lx(Fx) = avg # of offspring per capita at age x
      - lx(Fx)x = avg # of offspring per capita at time x, weighted by age x
    - - How long individuals survive
      - representation of survivorship
      - Type I typical of K-selected species
      - Type III, typical of r-selected species
      - Dependent on environment
      - Same species can display all 3
    - - Survivorship curves are plotted logarithmically
      - Take survivorship (lx) and multiply by 1000
      - Take log10 of this value
      - Plot against age to produce a figure
      - Ex: Type I curve
  - - - group of interacting species living in same location
      - shared environment
      - factors
        
        abiotic environment
        
        biotic interactions occur between species
        
        Range of interactions
        
        Beneficial interactions +
        
        Negative interaction -
        
        Facilitation (+/+)
        
        benefits both
        
        mutualism
        
        pollination
        
        Commensalism (0/+)
        
        Benefits 1 neutral to other
        
        Amensalism (0/-)
        
        Negative to 1 & neutral to other
        
        Competition (-/-)
        
        Both are negatively impacted
        
        Competition for resources
        
        Predation (+/-)
        
        Herbivory
        
        Parasitism
    - - Predator
        
        p
        
        Negative impact on prey
        
        Positively impacted by prey
      - Prey
        
        n
        
        Positive impact on predator
        
        Negatively impacted by predator
      - Population sizes influenced by each other
    - - r = intrinsic growth rate
      - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth
      - Logistic growth
      - similar model predator-prey growth