Please enable JavaScript.
Coggle requires JavaScript to display documents.
Exam 4 - Coggle Diagram
Exam 4
Pop. Genetics
Hardy-Weinberg Equation
1. Gene Pool: All of the alleles of every gene in a pop make up the gene pool. All pop us a group of individuals of the same species that occupy the same region and can interbreed w/ each other
Gene Pool: Allele & Genotype Relative frequencies:
Allele frequ; # of copies of an allele in a pop. divided by the total # of alleles for that gene in a pop.
Genotype freq.; # of individual w/ a particular genotype in a pop. divided by the total # of individuals in a pop.
-
!Allele Relative Frequency!: number of copies of an allele in a population / total number of all alleles for that gene in a population.
!Genotype Relative Frequency!: Number of individuals w/ a particular genotype in a population / total number of all individuals in a population.
H-W Equation: predicts an equilibrium-unchanging allele frequencies from generation to generation-if certain conditions exist in a population.
-
-
-
-
-
-
Frequencies in pop. add up to 1: dimorphic pop (2 alleles) such as our red an white flowers w/ alleles R & r.
- Alleles in the pop add up to 100% or 1.
- All genotypes in the pop add up to 100% or 1.
-
-
Assumptions of HW
1. Microevolution: - change in a pop's gene pool from gen to gen. - factors: mutation, natural selection, genetic drift, migration, nonrandom mating.
2. Mutation: - change in one of the nucleic acids, - some are apparent in phenotypes, - source of all new alleles, - must be in gametes to be inherited; male pollen sperm, female ovule egg
3. Polymorphism: - dimorphic; 2 phenotypes, dominant-recessive systems. - polymorph = many phenotypes in a pop.
4. Genetic drift: - random loss of alleles, - acts most strongly in small pop relative to large, - Bottleneck effect; lg pop diminished suddenly; natural catastrophe, migration. may inc. in size again but unlikely to regain iriginal diversity.
5. Nonrandom Mating: - plants choose their mates - pollinator vectors; pollination syndromes. - some of the ind. reproduce more than others; based on individual phenotypes.
5.2 (sexual selection):
- male-male comp.: excess of pollen grains, pollen tubes can interfere with one another.
- female choice: barriers on stigma surface preventing germination.
6. Migration, Gene Flow: - movement of alleles into an out of a pop; immigration/into, Emigration/out of. - can be impeded by; enviro., life hist. - Repercussions for; GMO and climate change, speciation.
-
-
9. Artificial Selection: selection by humans; inc. freq. of desired trait, elimination of undesirable traits. - crop breeders for thousands of years
-
Community Ecology
Pop. Demography
Pop. size over time: -- pop size (N) -- exponential growth; J-shaped curve, unlimited resources. -- logistic growth; S-shaped curve, typocal of a pop that self regulates and has a carry capacity (K)
Growth Models: r = intrinsic growth rate (relevant for r>0). N = pop size. K = carrying capacity. dN/dt = pop change over time. Exponential growth; dN /dt = rN. Logistic growth; dN/ dt = rN * the quantity 1 - N/K.
-
-
Plant strategies
-
Stress: -resource availability, light, water, nutrients. -growth inhibitors, temp. toxins.
Disturbance: - biotic, herbivory, pathogens, anthropogenic. -abiotic, fire, wind.
3 life stages: C-competitors, S-stress tolerators, R-ruderals.
-
Life History
Predict if the population will grow or shrink ecologists need to know birth and death rates for an organisms at different ages as well as the current age insects 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?
Population aid structure are there lots of young individuals? Old individuals? Reproductive age individuals? And similar questions
-
-
-
Heredity
Genetic Variation
1. Diploid Individual: --each chromosome has a partner. --homologous chromosomes (each from dif. parent). --resembles each other in size, shape, hereditary info. --interaction of genes on each set of chromosomes determines the genetic characteristics
2. Miosis --Ind Asrtmnt: --Metaphs 1: orientation of bialents is random --Metaphs 2: orientation of sister chomatids is random. -- usually 2n possibilities: ex, human w/ 46 chromosomes, 2^46=7.04 x 10^13
3. Crossing Over -prophs 1: synaptonemal complex forms. -mizes genes present in homologous chromospmes. - results in new combos not present in the chromosomes of parental cells. -usually 1 chiasma occurs btwn every pair of homologous chromosomes.
4. sexual repro. -new combo of alleles from each parent. -promotes heterozygosity. -advantages: genetic diversity, bet-hedging to novel enviro, multi deleterious alleles can bunch together and be eliminated, escape host-parasite neg. impact. --pollination: cross pollination vs self-pollination.
-
-
-
Mendelian Gen.
3 Principles
_1. Dominance; each ind. has unique genotype(<made up of alleles), phenotypes determined by alleles + enviro, no guarantee that an allele will manifest; Heterozygosity: one of 2 genes (dominant) has detectable effect on appearance. other gene has no visible effect(recessive). Homozygosity: both alleles are the same.
_2. Segregation: alleles separated from one another during meiosis, each gamete has only 1 allele for each gene., offspring inherit 2 alleles for a gene; one from each parent, inherit homologous chromosome. --in meiosis, 2 members of gene pair separate from each other. -- each gamete as and equal chance to inherit either one of the genes.
monohybrid cross: punnett square, cisual representation of offspring, monohybris is a cross btwn 2 homologous parents w/ dif. alleles.
_3. Independent Assortment -gene pairs are not related (homologous) segregate independently - gene pairs that are not linked segregate independently - 3:1 phenotypic ratio for each of the 2 alleles
-
-
