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Botany Exam 5 - Coggle Diagram

- - - - Each chromosome has a partner
      - Homologous chromosomes
      - Resemble each other in size, shape & 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 2n
        
        Ex: human with 46 chromosomes
        
        246 = 7.04 x 1013
    - - 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
        
        Principle of Dominance
        
        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
        
        Heterozygosity
        
        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
      - Segregation
        
        Principle of Segregation
        
        Alleles are segregated, separated, from one another during meiosis
        
        Each gamete contains only one allele for each gene
        
        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
      - Independent Assortment
        
        Principle of Independent Assortment
        
        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
    - - Punnett square
      - Visual representation of the offspring inheritance patterns
      - Monohybrid is a cross between 2 homozygous parents with different alleles.
    - - Parental
        
        True breeding
        
        Homozygous
      - F1
        
        First filial generation
        
        Heterozygotes
      - 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 individua
      - 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 effects of many genes
      - Example abscisic acid
      - Most traits
      - Continuous variation
      - Populations tend to have normal distribution
    - - One gene interacts with another
      - May interfere or mask
      - Ex: 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 influences several traits
      - Ex: awn of wheat
        
        Wheat with awns have greater yield than those without awns
    - - Selfer
        
        Small petals
        
        Flower early
        
        Seasonal drought
        
        Physiologically escape
      - Outcrosser
        
        Outcrosser
        
        Flower late
        
        Seasonal drought
        
        Physiologically tolerant
    - - Having more than two copies (2n) of a chromosome
      - Autopolyploid
        
        Failed meiosis
        
        Self fertilization
      - Allopolyploid
        
        Meiotic error
        
        Mismatch during mating
        
        Second mating creates matched pairs
    - - Wheat
      - Result of sequential hybrid doubling and quadrupling
      - Original ancestral species had 14 chromosomes
      - Durum wheat
        
        28 chromosome
        
        Tetraploid
        
        pasta
      - Bread wheat
        
        42 chromosome
        
        Hexaploid
        
        Gluten for lofty bread
    - - 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
- - - - Population size (N)
      - Exponential growth
        
        J-shaped curve
        
        Unlimited resources
      - Logistic growth
        
        S-shaped curve
        
        Typical of a 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 over dt equals r times N times the quantity one minus N divided by K
    - - Exponential growth
        
        dN/dt = rN
      - Logistic growth
        
        dN/dt = rN[(K-N)/K] =
        rN(1-N/K)
    - - r-selected
        
        Disturbed areas
        
        Weedy
        
        Annuals
        
        Little investment in defense
        
        Many, small fruits
        
        Grow exponentially
      - 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 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
    - - Calculate the net reproductive rate (R0)
      - Calculated by taking the sum of the offspring/individual column.
      - Represents the expected number of offspring an individual will produce over its lifetime in the population.
      - If R0>1, the population size increases.
      - If R0<1, the population size decreases, and if R0=1, then population size does not change.
    - - Calculate the mean generation time (G)
      - 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
      - The average age between parent and offspring
      - For humans, typically 20-35 years of age
    - - Calculate the intrinsic growth rate (r)
      - Calculated by taking the natural log of the net reproductive rate divided by the mean generation time.
      - If r>0, the population size increases.
      - If r<0, the population size decreases, and if r=1, then population size does not change.
    - - 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
    - - Survivorship curves are plotted logarithmically
      - Take survivorship (lx) and multiply by 1000
      - Take the log10 of this value
      - Plot against age to produce a figure
      - Example: Type I curve
  - - - 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 & neutral to other
      - Competition (-/-)
        
        Both are negatively impacted
        
        Competition for resources
      - Predation (+/-)
        
        Herbivory
        
        Parasitism
    - - Predator
        
        Negative impact on prey
        
        Positively impacted by prey
        
        P
      - Prey
        
        Positive impact on predator
        
        Negatively impacted by predator
        
        N
      - Population sizes are influenced by each other
    - - r = intrinsic growth rate
      - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth
      - Logistic growth
      - Can similar model predator-prey growth and the impact each has on the other
    - - 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
    - - 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
    - - Prey population change
        
        The number of prey N = 1200
        
        rate of capture or the predation constant a = 0.004
        
        Intrinsic growth rate, r = 0.7
        
        Number of predators, P = 130
        
        dN/dt = rN-aNP
      - Predator population change
        
        N = 1200
        
        a = 0.004
        
        f = 0.025 predator birth constant
        
        q = 0.12 predator death constant
        
        P = 130 number of predators
        
        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
    - - 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
    - - Number of copies of an allele 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 alleles for that gene in a population
    - - Number of individuals with a particular genotype in a population divided by the total number of all individuals in a population
    - - Number of individuals with a particular genotype in a population divided by the total number of all individuals in a population
    - - Number of individuals with a particular genotype in a population divided bytThe total number of all individuals in a population
    - - predicts an equilibrium-unchanging allele and genotype frequencies from generation to generation-if certain conditions exist in a population
      - No new mutations
      - No genetic drift. The population is so large allele frequencies do not change due to random sampling effect
      - No migration
      - No natural selection
      - Random mating
      - provides a quantitative relationship between the allele and genotype frequencies
    - - Consider the following phenotypes & genotypes
        
        45 red flowered, homozygous plants
        
        25 red flowered, heterozygous plants
        
        23 white flowered plants
      - Frequency of r: # copies of allele r over Total number of alleles (R & r)
    - - 45 RR
      - 25 Rr
      - 23 rr
      - Freq of individuals with rr genotype:
        
        =23/(45+25+23)= 23/93 = 0.25
    - - Consider a dimorphic population (2 alleles) such as our red and white flowers with alleles R & r
        
        All alleles in the population add up to 100% or 1
        
        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
    - - 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.
    - - we always use p and q rather than choosing an upper and lowercase letter to represent alleles:
      - The frequency of the dominant allele is represented by p
      - The frequency of the recessive allele is represented by q
      - Thus p+q=1
      - 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
  - - - Changes in a population’s gene pool from generation to generation
      - Factors
        
        Mutation
        
        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
        
        Natural selection
        
        One allele selectively advantageous
        
        In this example, 2 (triangle) has more vigorous offspring
        
        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
        
        Genetic drift
        
        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
        
        Migration, Gene Flow
        
        Movement of alleles into and out of a population
        
        Immigration
        
        Into
        
        Emigration
        
        Out of
        
        Can be impeded by #
        
        The environment
        
        Life history
        
        Repercussions for
        
        GMO and
        
        climate change
        
        speciation
        
        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
    - - 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
    - - Bottleneck from long distance dispersal
      - Followed by adaptive radiation
      - Example: Hawaiian lobeliads
    - - Selection by humans
        
        Increased frequency of desired trait
        
        Elimination of undesired traits
      - Crop breeders for thousands of years
      - Crop breeders for thousands of years
  - - - Find your Min & Max values
      - Determine the number of bins
      - Count the number of observations for each bin
      - Draw bars for each bin with the frequency
    - - Death does not mean natural selection has occurred
      - Differential survival
      - Survival due to phenotypes that are heritable
        
        Phenotype coded by genotype
    - - 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