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Exam 5 - Coggle Diagram

- - - - Mixes the genes present in homologous
      - Results in new combinations not present in the chromosomes of the parental cells
      - Synaptonemal complex
      - Usually at least one chiasma occurs between every pair of homologous chromosomes
      - During Prophase I
    - - New combination of aalleles
      - Promotes heterozygosity
      - Advantages include
        
        Genetic diversity
        
        Bet-hedging to novel environments
        
        Escape host-parasite negative impacts
        
        Multiple deleterious alleles can be bunched together and eliminated
      - Pollination
        
        Cross pollination vs
        
        Self-pollination
    - - During Metaphase II
        
        Orientation of sister scromatids is random
      - In general, the possibilities are 2^n
        
        Ex: human with 46 chromosomes
        
        2^46 = 7.04 x 10^13
      - During metaphase I
        
        Orientation of bivalents is random
    - - Resemble each other in size, shape & hereditary information
      - Each homolog is from a different parent
      - Homologous chromosomes
      - Interactions of genes on each sets of chromosomes determines the genetic characteristics
      - Each chromosome has a partner
  - - - 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 contains only one allele for each gene
      - Each gamete has an equal chance to inherit either one of the genes
      - Alleles are segregated, separated from one another during meiosis
    - - Gene pairs that are not linked segregate independently
      - Evidence provided from a dihybrid cross
        
        3:1 phenotypic ration for each of the 2 alleles
      - Gene pairs that are not related (homologs) segregate independently
    - - Genotype is made up of alleles
      - Phenotypes determined by these alleles (and the environment)
      - Each individual has a unique genotype
      - There is no guarantee that an allele will manifest
        
        Heterozyogosity
        
        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
    - - visual representation of the offspring inheritance patterns
      - Monohybrid is a cross between 2 homozygous parents with different alleles
      - Punnett square
    - - Segregation
      - Independent Assortment
      - Dominance
    - - Parental
        
        True breeding
        
        Homozygous
      - F1
        
        First filial
        
        Heterozygous
      - For reference
      - Genotypic ratio
        
        Allele combinations
      - Phenotypic ratio
        
        Trait combinations
      - same as monohybrid but with two alleles #
  - - - Point mutation
        
        Single nucleotide change
      - Chromosome mutation
        
        Duplication
        
        part of the chromosome has doubled
        
        Inversion
        
        Piece rotates 180
        
        Translocation
        
        Exchange of parts between 2 nonhomologous chromosomes
        
        Deletion
        
        Segments of chromosome are lost
        
        Transposons
        
        Movable genetic element
        
        Jumping genes
      - Changes in the genetic makeup of an individual
    - - Chromosome inherited same as parent
      - Only 2 gamete types possible rather than 4
      - Fail to mix alleles across homologs
    - - Selfer
        
        Flower early
        
        Seasonal droughts
        
        Small petals
        
        Physiologically escape?
      - Outcrosser
        
        Large petals
        
        Flower late
        
        Seasonal drought
        
        Physiologically tolerant?
    - - Example abscisic acid
      - Most traits
      - Phenotype is cumulative result of combined effects of many genes
      - Continuous variation
      - Multiple genes for one character
      - Populations tend to have normal distribution
    - - Inheritance of a single gene which visibly influences several traits
      - Ex: awn of wheat
        
        Wheat with awns have greater yield than those without
      - Single gene with multiple effects on the phenotype
    - - May interfere or mask
      - Ex: digitalis petal color
        
        One gene impacts red intensity
        
        d light red
        
        D dard red
        
        Pigment location
        
        w throughout corolla
        
        W spots of nectar guide
      - One gene interacts with another
    - - 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
    - - 4 haploid genotypes
      - Not produced in equal numbers
        
        Recombinants less abundant
        
        Parentals more abundant
    - - Phenotype of heterozygote is intermediate between those of parent homozygotes
      - Snapdragons
        
        Red x White = pink
    - - Autopolyploid
        
        Failed meiosis
        
        Self-fertilization
      - Allopolyploid
        
        Meiotic error
        
        Mismatch during mating
        
        Second mating creates matched pairs
      - Having more than two copies (2n) of a chromosome
      - Polyploid Example
        
        Wheat
        
        Original ancestral species had 14 chromosomes
        
        Durum wheat
        
        28 Chromosome
        
        Tetraploid
        
        Pastaa
        
        Bread wheat
        
        42 Chromosome
        
        Hexaploid
        
        Gluten for lofty bread
        
        Result of sequential
        
        Strawberry
        
        Produce diploid gametes
        
        Required for meiosis to occur properly
        
        During fertilization 2 diploid gametes fuse
        
        Prevent microtubule formation
        
        Results in tetraploid (4n)
        
        Chemically induced
    - - 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
      - Polyploid mask deleterioous recessive alleles
- - - - Logistic growth
        
        S-shaped curve
        
        Typical of a population that
        
        Self regulates
        
        Has a carrying capacity (K)
      - Population size (N)
      - Exponential growth
        
        Unlimited resources
        
        J-shaped curve
    - - Result in die off
        
        Limited resources
      - Overshoot K
    - - K = carrying capacity
      - dN/dt = population change over time
      - N = population size
      - Exponential growth
        
        dN over dt equals r times N
      - r = intrinsic growth rate
      - Logistic growth
        
        dN over dt equals r times N times the quantity one minus N divided by K
    - - Expontential growth
        
        dN/dt = rN
      - logistic growth
        
        rN(1-N/K)
        
        dN/dt = rN[(K-N)/K] =
    - - r-selected
        
        Weedy
        
        Annuals
        
        Diisturbed areas
        
        Little investment in defense
        
        Grow exponentially
        
        Many, small fruits
      - K-selected
        
        Fluctuate around carrying capacity
        
        Fairly stable habitats
        
        Perennials
        
        Ivenst in defenses
        
        Resource-intensive fruits
    - - Many strategies exist
      - Grime's model
        
        Disturbance
        
        Biotic
        
        Pathogens
        
        Anthropogenic
        
        Herbivory
        
        Abiotic
        
        Fire
        
        Wind
        
        3 life stages
        
        C - Competitors
        
        S - stress tolerators
        
        R - ruderals
        
        Stress
        
        Resource availability
        
        Nutrients
        
        Light
        
        Water
        
        Growth inhibitors
        
        Temperature
        
        Toxins
      - Plants must make trade-offs due to environmental necessities
  - - - Life tables summarize birth and death rates for organisms at different stages of their lives.
      - Population age structure--Are there lots of: young individuals? Old individuals? Reproductive age individuals?; and similar questions
      - To predict if a population will grow or shrink, ecologists need to know birth and death rates for organisms at different ages as well as the current age and sex makeup of the population.
      - Population growth rate--How fast is the population size growing (or shrinking)? Population survivorship patterns--Does most mortality occur in the very young? The very old? Or equally across all ages?
    - - 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
      - Nx - Number of individuals alive at age x
      - Fx= average number of offspring born to a female while she is age x
      - x = age
      - 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
    - - Represents the expected number of offspring an individual will produce over its lifetime in the population.
      - If R0>1, the population size increases.
      - Calculated by taking the sum of the offspring/individual column.
      - If R0<1, the population size decreases, and
      - Calculate the net reproductive rate (R0)
      - if R0=1, then population size does not change.
    - - Type I, typical of K-selected species
      - Type III, typical of r-selected species
      - Visual representation of survivorship
      - Dependent on environment
      - How long did individuals survive
      - Same species can display all 3
    - - Take the log10 of this value
      - Plot against age to produce a figure
      - Take survivorship (lx) and multiply by 1000
      - Example: Type I curve
      - Survivorship curves are plotted logarithmically
  - - - Prey
        
        Positive impact on predator
        
        Negatively impacted by predator
        
        N
      - Population sizes are influenced by each other
      - Predator
        
        Negative impact on prey
        
        Positively impacted by prey
        
        P
      - Predator-prey cycling
        
        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
        
        At low prey and predator population sizes, prey increase exponentially
        
        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 = population change over time
      - Exponential growth
      - K = carrying capacity
      - Logistic growth
      - N = population size
      - Can similar model predator-prey growth and the impact each has on the other
      - r = intrinsic growth rate
    - - Facilitation (+/+)
        
        Benefits both
        
        Mutualism
        
        Pollination
      - Commensalism (0/+)
        
        Benefits one, neutral to the other
      - Negative interaction -
      - Amensalism (0/-)
        
        Negative to one & neutral to other
      - Beneficial interactions +
      - Competition (-/-)
        
        Both are negatively impacted
        
        Competition for resources
      - Range of interactions
      - Predation (+/-)
        
        Herbivory
        
        Parasitism
    - - dN/dt = rN-aNP
        
        N=number of prey individuals
        
        a=predator’s per capita attack rate
        
        Number of prey eaten per predator per unit time
        
        r=intrinsic rate of increase for prey
        
        P= number of predator individuals
        
        dN/dt=rate of change with time of the prey population
      - dP/dt = faNP-qP
        
        f=constant, indicating predator’s efficiency at converting the prey it has eaten into new predators
        
        q=predator’s per capita mortality rate
        
        dP/dt= rate of change with time of predator population
    - - 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
      - A group of actually or potentially interacting species living in the same location
    - - Prey population change
        
        Intrinsic growth rate, r = 0.7 = and
        
        Number of predators, P = 130?
        
        rate of capture or the predation constant a = 0.004
        
        dN/dt = rN-aNP
        
        The number of prey N = 1200,
      - Predator population change
        
        f - 0.025 predator birth constant,
        
        q = 0.12 predator death constant
        
        a = 0.004,
        
        and P = 130 number of predators
        
        N = 1200,
        
        dP/dt = faNP-qP
- - - - 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
      - Gene pool: Allele & Genotype Relative frequencies
        
        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
    - - Divided by
      - The total number of all alleles for that gene in a population
      - Number of copies of an allele in a population
    - - Divided by
      - The total number of all individuals in a population
      - Number of individuals with a particular genotype in a population
    - - No migration
      - No natural selection
      - No genetic drift. The population is so large allele frequencies do not change due to random sampling effects
      - Random mating
      - No new mutations
    - - All genotypes in the population add up to 100% or 1
      - Red & White flower examples
        
        Allele frequencies
        
        r = 0.38, R = 0.62
        
        0.38 + 0.62 = 1
        
        Genotypic frequencies
        
        rr = 0.25, RR = 0.48, Rr = 0.27
        
        0.25 + 0.48 + 0.27 = 1
      - All alleles in the population add up to 100% or 1
    - - Genotypic frequency:
        
        Rr= 0.24+0.24= 0.48
        
        rr= 0.14
        
        RR= 0.38
      - 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.
    - - If, instead, we always use p and q rather than choosing an upper and lowercase letter to represent alleles:
        
        The frequency of the recessive allele is represented by q
        
        Thus p+q=1
        
        The frequency of the dominant allele is represented by p
        
        Therefore (p+q)2=12
        
        And p2+2pq+q2=1
        
        p2= genotypic frequency of RR
        
        2pq= genotypic frequency of Rr
        
        q2= genotypic frequency of rr
    - - Microevolution
        
        Changes in a population's gene pool from generation to generation
        
        Factors
        
        Natural selection
        
        Over time, individuals with the 2 genotype are able to reproduce more and grow in numbers
        
        The overall vigor of the population grows
        
        So does population size
        
        One allele selectively advantageous
        
        Genetic drift
        
        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
        
        Random loss of alleles
        
        Migration, gene flow
        
        Can be impeded by
        
        The environment
        
        Life history
        
        Repercussions for
        
        GMO and
        
        climate change
        
        speciation
        
        Movement of alleles into and out of a population
        
        Immigration - into
        
        Emigration - out of
        
        Mutation
        
        Some are apparent in phenotype
        
        Source of all new alleles
        
        Change in one of the nucleic acids
        
        Must be in gametes to be inherited
        
        Male pollen sperm
        
        Female ovule egg
        
        Nonrandom mating
        
        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
        
        Polymorphism
        
        Example: Aquilegia
        
        Color variation
        
        Polymorph = many phentypes in a population
        
        Spur-length variation
        
        Dimorphic
        
        2 phenotypes
        
        Dominant-recessive systems
        
        Can be due to a single nucleotide polymorphism
        
        Adaptive radiation
        
        Followed by adaptive radiation
        
        Example: Hawaiian lobeliads
        
        Bottleneck from long distance dispersal
        
        Artificial selection
        
        Crop bredders for thousands of years
        
        Example Brassica
        
        Selection by humans
        
        Elimination of undesired traits
        
        Increased frequency of desired trait
  - - - y=Fitness (number of offspring produced) x=Trait
      - y=Average size (in population) x=Trait
      - y=frequency x=Trait
    - - Differential survival
      - Survival due to phenotypes that are heritable
        
        Phenotype coded by genotype
      - Death does not mean natural selection has occurred
    - - 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
      - Distinct alleles may encode proteins of differing functions
      - Over the course of many generations, allele frequencies of many different genes may change through natural selection
      - Within a population there is allelic variation arising from various factors such as mutations causing differences in DNA sequences
      - This significantly alters the characteristics of a species