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Exam 5 - Coggle Diagram

- - - - each homolog in a pair comes from respective parent (m f)
        
        cross pollination
      - interactions of genes determine phenotype
        
        independent assortment (crossing over)
        in metaphase I and metaphase II
        
        Synaptonemal complex forms
        
        Possibilities are 2n, in humans 246 = 7.04 x 1013
    - - resistance to novel environments
      - Remove deleterious alleles via nat selection
      - resistance to host parasites
  - - - Dominance
        
        Each individual has a unique genotype (alleles)
        
        Phenotypes determined by alleles and environment
        
        Allele manifestation
        
        Heterozygous
        
        One of two genes (dominant & recessive)
        
        Homozygous
        
        Both recessive or both dominant
      - Segregation
        
        Alleles are segregated and each gamete contains only one allele for each gene
        
        Punnett squares
      - Independent Assortment #
        
        Gene pairs that are not related (homologs) segregate independently
        
        Gene pairs that are not linked segregate
        
        Dihybrid crosses
  - - - Phenotype of heterozygote is intermediate between parents
      - Snapdragons D red x d white = Dd pink
    - - Common to have more than 2 alleles per locus
        
        Dominance hierarchy can vary
      - Figuring out alleles is complex
    - - Changes in genetic makeup
      - Point mutation
        
        single nucleotide change
      - Chromosomal mutation
        
        Deletion
        
        segments of chromosome are lost
        
        Duplication
        
        part of chromosome has doubled
        
        Inversion
        
        piece rotates 180, different amino acids
        
        Translocation
        
        exchange of parts between 2 non-homologous chromosomes (not crossing over)
        
        Transposons
        
        moveable genetic elements (jumping genes)
      - Not crossing over
        
        failing to mix alleles across homologs
        
        only 2 gamete types rather than 4
    - - multiple genes for one character
      - Phenotype is determined by combination of genes
      - Continuous variation with a normal distribution
    - - One gene interacts with another
      - May interfere or mask phenotype
      - ex. one gene impacts red intensity, other impacts pigment location. messes with predicted phenotypes
    - - 4 haploid genotypes that are not produced in equal numbers
      - Recombinants are less abundant
      - Parentals more abundant, crossing over doesnt always occur
    - - single gene with multiple effects on phenotype
      - ex. wheat awn. gene that codes for having an awn also results in large berries
    - - Having more than two copies of a chromosome, unreduced gametes
      - autopolyploid (asexual)
        
        failed meiosis
        
        self fertilization
      - allopolyploid (sexual)
        
        error in meiosis
        
        mating mismatch
        
        second mating creates matched pairs
      - thought to have given rise to new plant linages
        
        masks deleterious recessive traits
        
        relaxes pressure from selection, accumulates eventually beneficial trait
        
        2 major ancient polyploids, seed plants and extant angiosperms
        
        allows for innovations
- - - - alleles of every gene in a group of individuals that can interbreed with one another
      - allele frequency
        
        number of allele copies/ total number of all alleles for gene
        
        actual allele frequencies
      - genotype frequency
        
        number of individuals with particular genotype/ total number of individuals in population
        
        actual genotypic frequencies
    - - provides a quantitative relationship between allele and genotype frequencies
      - predicts if certain conditions exist
        
        no new mutations
        
        no genetic drift (no random sampling)
        
        no migration
        
        no natural selection
        
        random mating
      - frequency of dom allele is p, frequency of reces allele is q
      - p+q=1, then (p+q)^2=1^2, therefore p^2+2pq+q^2=1
      - p^2= gene frequency of RR
      - 2pq= gene frequency of Rr
      - q^2= gene frequency of rr
  - - - caused by mutations #
        
        polymorphism
        
        dimorphic, 2 phenotypes, dom-recess
        
        polymorph, many phenotypes
        
        genetic drift
        
        random loss of alleles
        
        bottleneck effect, large population reduced suddenly
        
        unlikely to regain original diversity
        
        non-random mating
        
        plants "choose" mates through pollination vectors/syndromes
        
        some individuals reproduce more often
        
        male-male competition through pollen grains
        
        female choice through barriers on stigma surface
        
        gene flow (migration)
        
        movement of alleles in and out of population
        
        impacted by environment and life history
        
        repercussions for gmos, climate change and speciation
        
        natural + artificial selection
        
        one allele is selectively advantageous
        
        over time, this leads to domination of gene
  - - - directional selection
        
        hogs (predator) come in preferring cacti with smaller amounts of spines.
        
        selective pressure causes a rise in population of cacti with more spines (to survive)
        
        spined cacti
      - stabilising selection
        
        reduction in variety can reduce the environmental stability of the plant
        
        If a parasitic population that preferred cacti with more spines came in, it would reduce the genetic variation of the already pressured cacti
      - Disruptive selection
        
        if humans came in looking for cacti to take home, they would choose the median and reduce that population, causing an M-shaped curve
        
        Can redistribute variation, but looks like a bi-variant
- - - - exponential growth
        
        j-shaped curve
        
        unlimited resources, not regulated
        
        dN/dt = r*N
      - logistic growth
        
        S- shaped curve
        
        population that self-regulates and/or has a carrying capacity
        
        dN/dt = r*N(1-N/K)
    - - overshooting results in a die off due to limited resources
      - causes an unstable equilibrium
    - - r- intrinsic growth rate
      - N- population size
      - K- carrying capacity
      - dN/dt- population size over time
    - - r-selected (ex. dandelion)
        
        grow exponentially
        
        weedy, small fruits
        
        annuals with little investment in defense
        
        disturbed areas
      - k-selected (ex. avocado)
        
        fluctuate population size around carrying capacity
        
        perennials with defenses
        
        resource-intensive fruits
        
        fairly stable habitats
    - - Plants must make trade-offs with environmental necessities
      - Grime's model
        
        Stress
        
        Resource availability (water, nutrients, light)
        
        Growth inhibitors (temperature, toxins)
        
        Disturbance
        
        Biotic (herbivory, pathogens, anthropogenic)
        
        Abiotic (fire, wind)
        
        3 life stages
        
        C- competitors
        
        S- stress tolerators
        
        R- ruderals
  - - - x = age
      - Nx= number of individuals alive at age x
      - Sx= proportion of individuals of age x that survive to age x+1; Nx+1/Nx
      - lx= proportion of individuals that survive from birth (age 0) to age x; Nx/N0
      - Fx= average number of offspring born to a female while she is age x
      - lx(Fx) = average number of offspring per capita at age x
      - lx(Fx)x = average number of offspring per capita at time x, weighted by age x
    - - Calculated by taking the sum of the offspring/individual column.
      - If R0>1 , population increase
      - If R0<1 , population decrease
      - If R0=1 , no population change
      - Represents the expected number of offspring an individual will produce over its lifetime in the population.
    - - Calculated by taking the sum of the Age-weighted fecundity column and then dividing by the net reproductive rate
      - Represents average time between two consecutive generations in the lineage of a cohort
    - - r= ln*R0/ G
    - - visual representation of survivorship
      - Type I: k-selected species
      - Type III: r-selected species
  - - - group of actually or potentially interacting species in the same location
      - shared environment and network influence on one another
      - affecting factors: abiotic environment, biotic interactions
    - - Facilitation (+/+)
      - Commensalism (0/+)
      - Amensalism (0/-)
      - Competition (-/-)
      - Predation (+/-)
        
        predator-prey cycling
        
        At low prey and predator population sizes, prey increase exponentially
        
        As more food for predators is available, predator survival and reproductive success increases, resulting in predator population growth following that of their prey
        
        As predator populations increase, prey death rate exceeds birth rate, resulting in prey decline
        
        As prey number declines, there is not enough food to sustain a high predator population and thus predator death rate exceeds that of birth rate
        
        Lotka-volterra models
        
        dN/dt = rN-aNP
        
        dN/dt= rate of change with time of the prey population
        
        r= intrinsic rate of increase for prey
        
        N= number of prey individuals
        
        a= number or prey eaten per predator per unit of time
        
        P= number of predator individuals
        
        killing potential of predator to prey
        
        dP/dt = faNP-qP
        
        dP/dt= rate of change with time of predator population
        
        f= constant, indicating predator’s efficiency at converting the prey it has eaten into new predators
        
        q= predator’s per capita mortality rate
        
        amount of prey needed for population growth