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Exam 4 - Coggle Diagram

- - - - Each chromosome has a partner
      - Homologous chromosomes
      - Resemble each other In size, shape, and hereditary Information
      - Each homolog Is from a different parent
      - Interactions of genes on each sets of chromosomes
        determines the genetic characteristics
    - - During metaphase I
        
        Orientation of bivalents Is random
      - During metaphase II
        
        Orientation of sister chromatids Is random
      - In general, the possibilities are 2^n
        
        Example: human with 46 chromosomes = 2^46 = 7.04 x 10^13
    - - During prophase I
      - Synaptonemal complex forms
      - Mixes the genes present In homologous chromosomes
      - Results In new combinations not present
        In the chromosomes of the parental cells
      - Usually at least one chiasma occurs between
        every pair of homologous chromosomes
    - - New combination of alleles from each parent
      - Promotes heterozygosity
      - Advantages Include:
        
        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 a unique genotype
      - Genotype Is made up of alleles
      - Phenotypes determined by these alleles (and the environment)
      - There Is no guarantee that an allele will manifest
        
        Heteroygosity
        
        One of 2 genes (dominant allele) has a
        detectable effect on an organism's appearance
        
        The other gene has no discernable effect (recessive allele)
        
        Homozygosity
        
        Both alleles are the same
    - - Alleles are segregated, separated,
        from one another during meiosis
      - Each gamete contains only one allele for each parent
      - Offspring Inherit 2 alleles for a gene
        
        One from each parent
        
        Inherit a homologous chromosome
      - During meiosis, 2 members of a
        gene pair separate from each other
      - Each gamete has an equal chance
        to Inherit either one of the genes
    - - Punnett square
      - Visual representation of the offspring Inheritance patterns
      - Monohybrid Is a cross between 2 homozygous
        parents with different alleles
    - - Gene pairs that are not related (homologs)
        segregate Independently
      - Gene pairs that are not linked segregate Independently
      - Evidence provided from a dihybrid cross
        
        3:1 phenotypic ratio for each of the 2 alleles
    - - Parental
        
        True breeding
        
        Homozygous
      - F1 - first filial generation
      - Genotypic ratio - allele combinations
      - Phenotypic ratio - trait combinations
  - - - Phenotype of heterozygote Is Intermediate
        between those of parent homozygotes
      - Snapdragons
        
        Red x white = pink
    - - Many populations have more than 2 alleles for a particular locus
      - Punnett square theoretical crossing works similar
      - Breeding experiments to determine dominance
      - Figuring out alleles Is complex
    - - Changes In the genetic makeup of an Individual
      - Point mutation
        
        Single nucleotide change
      - Chromosome mutation
        
        Deletion - segments of chromosome are lost
        
        Duplication - part of the chromosome has doubled
        
        Inversion - piece rotates 180
        
        Translocation - exchange of parts between
        2 nonhomologous chromosomes
        
        Transposons - movable genetic element & jumping genes
    - - Fail to mix alleles across homologs
      - Chromosome Inherited same as parent
      - Only 2 gamete types possible rather than 4
    - - Multiple genes for one character
      - Phenotype Is cumulative result of combined
      - Example abscisic acid
      - Most traits
      - Continuous variation
      - Populations tend to have normal distribution
    - - One gene Interacts with another
      - May Interfere or mask
      - Example: digitalis petal color
        
        One gene Impacts red Intensity
        
        d light red
        
        D dark red
        
        Pigment location
        
        w throughout corolla
        
        W spots of nectar guide
    - - 4 haploid genotypes
      - Not produced In equal numbers
        
        Recombinants less abundant
        
        Parentals more abundant
    - - Single gene with multiple effects on the phenotype
      - Inheritance of a single gene which visibly Infuences several traits
      - Example: awn of wheat
        
        Wheat with awns have greater yield than those without awns
    - - Having more than two copies (2n) of a chromosome
      - Autopolyploid
        
        Failed meiosis
        
        Self fertilization
      - Allopolyploid
        
        Meiotic
        
        Mismatch during mating
        
        Second mating creates matched pairs
      - Example
        
        Wheat
        
        Result of sequential hybrid doubling and quadrulpling
        
        Original ancestral species had 14 chromosomes
        
        Durum wheat
        
        28 chromosome
        
        Tetraploid
        
        Pasta
        
        Bread wheat
        
        42 chromosome
        
        Hexaploid
        
        Gluten for lofty bread
        
        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 that eventually result In beneficial trait
      - 2 groups of ancient duplications
        
        Common ancestor of seed plants
        
        Common ancestor of extant angiosperms
- - - - All of the alleles of every gene In a
        population make up the gene pool
      - A population Is a group of Individuals of the same species that occupy the same region and can Interbreed with each other
      - Allele frequency #
        
        Number of copies of an allele In a population divided
        by the total number of alleles for that gene In a population
      - Genotype frequency
        
        Number of Individuals with a particular genotype In a population divided by the total number of Individuals In a population
        #
    - - No new mutations #
      - No genetic drift - the population Is so large allele
        frequencies do not change due to random sampling effects #
      - No migration
      - No natural selection #
      - Random mating
    - - The frequency of gametes carrying a particular
        allele Is equal to the allele frequency for
        a population In Hardy-Weinberg equilibrium
      - Multiplying the allele frequencies gives the
        proportion of each allele combination In the population
  - - - Changes In a population's gene pool
        from generation to generation
      - Factors
        
        Mutation
        
        Natural selection #
        
        Genetic drift #
        
        Migration
        
        Nonrandom mating
    - - Change In one of the nucleic acids
      - Some are apparent In phenotype
      - Source of all new alleles
      - Must be In gametes to be Inherited
        
        Male pollen sperm
        
        Female ovule egg
    - - Dimorphic
        
        2 phenotypes
        
        Dominant-recessive systems
      - Polymorph = many phenotypes In a population
      - Example: Aquilegia
      - Color variation
      - Spur-length variation
      - Can be due to a single nucleotide polymorphism
    - - Random loss of alleles
      - Acts most strongly In small populations relative to large
      - Bottleneck effect
        
        Large population diminished suddenly
        
        Natural catastrophe
        
        Migration
        
        May Increase In size again but unlikely to regain original diversity
    - - Plants "choose" their mates
      - Pollinator vectors
        
        Pollination syndromes
      - Some of the Individuals reproduce more than others
        
        Based on Individual phenotypes
      - Sexual selection
        
        Male-male competition
        
        Excess of pollen grains
        
        Pollen tubes can Interfere with one another
        
        Female choice
        
        Barriers on stigma surface preventing germination
    - - Movement of alleles Into and out of a population
        
        Immigration - Into
        
        Emigration - out of
      - Can be Impeded by the environment or life history
      - Repercussions for GMO and climate change and speciation
    - - Bottleneck from long distance dispersal
      - Followed by adaptive radiation
      - Example: Hawaiian lobeliads
    - - One allele selectively advantageous
      - Overtime, Individuals with the more vigorous offspring
        are able to reproduce more and grow In numbers
      - The overall vigor and population size grow
    - - Selection by humans
        
        Increased frequency of desired trait
        
        Elimination of undesired traits
      - Crop breeders for thousands of years
      - Example: Brassica
  - - - Within a population there Is allelic variation arising from various factors such as mutations causing differences In DNA sequences
      - Distinct alleles may encode proteins of differing functions
      - Some alleles may encode proteins that enhance
        an Individual's survival or reproductive capacity
      - Individuals with beneficial alleles are
        more likely to survive and reproduce
      - Over the course of many generations, allele frequencies
        of many different genes may change through natural selection
      - This significantly alters the characteristics of a species
      - The net result of natural selection Is a
        population that Is better adapted to Its environment
        and/or more successful at reproduction
- - - - Population size (N)
      - Exponential growth
        
        J-shaped curve
        
        Unlimited resources
      - Logistic growth
        
        S-shaped curve
        
        Typical of a population that self regulates
        and has a carrying capacity (K)
    - - Overshoot K
      - Result In die off from limited resources
    - - r = Intrinsic growth rate
      - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth - dN/dt = rN
      - Logistic growth - dN/dt = rN(1-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
        
        3 life stages
        
        C - competitors
        
        S - stress tolerators
        
        R - ruderals
  - - - x = age
      - Nx = number of Individuals 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 to age x (Nx/No)
      - 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
    - - How long did Individuals survive
      - Visual 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
  - - - A group of actually or potentially Interacting
        species living In the same location
      - Bound together by a shared environment and a
        network of Influence each species has on the other
      - Factors affecting Interactions Include
        
        Abiotic environment
        
        Biotic Interactions that occur between species
    - - Range of Interactions
      - Beneficial Interactions (+)
      - Negative Interaction (-)
      - Facilitation (+/+)
        
        Benefits both
        
        Mutualism
        
        Pollination
      - Commensalism (0/+)
        
        Benefits one, neutral to the other
      - Amensalism (0/-)
        
        Negative to one and neutral to the other
      - Competition (-/-)
        
        Both are negatively Impacted
      - 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 are Influenced by each other
    - - At low prey and predator population
        sizes, prey Increases 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
    - - 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 = predator's per capita attack rate
        
        Number of prey eaten per predator per unit time
        
        P = number of predator Individuals
      - 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