Exam II HG - Fox 2021

Mendel's Monohybrid Cross: Parental generation (P1)- Filial Generation (F1)- Filial Generation (F2)-

- Both are true breeders - Are hybrids, not true breeders -Result of Self-cross, 1/2 true breeders, 1/2 not true breeders

Heterogametic- Homogametic- X-Chromosome characteristic- Y-Chromosome characteristic-

-2 different sex chromosomes (xy) -2 of the same sex chromosomes (xx) -Larger (155 million bp), more genes (1500) -Smaller (23 million bp), less genes (50)

Allele frequencies rarely stay constant and change when

-Non-random mating -Migration -Genetic drift -Mutation (rare) -Natural selection

Hardy Weinberg Equilibrium Assumptions

-Population is large -Random mating -No migration, genetic drift, mutation, natural selection

Y Chromosome Characteristics: PAR1 and PAR2- MSY Region- SRY Region-

-Pseudoautosomal regions, 63 pseudoautosomal genes (means it has counterparts on the X as well -Male Specific Region of the Y chromosome, lots of palindrome sequences, fertility genes -Sex determining Region of the Y chromosome, steers development to male or female route

How to examine single traits: Monohybrid cross- True breeders- Parental Generation- Filial Generation- Hybrid-

-crossing of two individuals that differ in a single given trait. These parents are typically True Breeders. -individuals that only produce offspring with the same traits, thus their alleles are homozygous -(aka P1) the parents being crossed -(aka F1, F2, etc) the subsequent offspring of the P1 generation being crossed -the offspring of the cross between two True Breeders, thus the F1 will have different alleles.

Genotype- Phenotype- Wild-type- Mutant- Mutation-

-the allele combination of an individual that causes a particular trait (ex. tall plants could be (TT) or (Tt) & short plants would be (tt) -the physical expression of a gene's trait (ex. tall or short plants) -the most common expression of an allele combination in a population -an allele that differs from the wild-type population (alters the phenotype) -change in a protein encoding gene that affects the phenotype

What Mendel Learned: Law of dominance- Dominant- Recessive-

-when 2 different alleles for a single trait, one allele is dominant over the recessive allele -allele that is expressed when present in one copy (masks the other allele) -allele whose expression is masked by another allele (the dominant allele) -Hybrids "hide" the expression of a trait. -Tall plants could be TT or Tt -Shows hybrid (Tt) that the T (tall) is expressed while the t (short) is hidden

Phenotypic Forms when mutations in SRY pathway occur:

1. Androgen insensitivity syndrome: mutation causes absence of androgen receptor, genotype is Male (XY), but phenotype is Female 2. 5-alpha reductase deficiency: mutation so that testosterone is not converted to DHT, internal structures are Male, but external structures are Female 3. Congenital adrenal hyperplasia: mutation causes testosterone & DHT to accumulate, Males enter puberty at age 3, females have male characteristics

2 forms of Eugenics

1. Positive 2. Negative

Different Dominance Relationships: Complete dominance- Incomplete dominance- Codominance-

1. one allele is expressed, the other is masked 2. heterozygote has an intermediate phenotype between the homozygous dominant & homozygous recessive forms - (Ex. Familial hypercholesterolemia) 3. different alleles are both expressed in the heterozygote - (ex. ABO blood group)

Criteria for Y-linked inheritance traits

1.All males are affected 2.Fathers will pass on to All sons 3.Fathers cannot pass on to daughters

criteria for X-linked recessive trait

1.Always expressed in males 2.Heterozygous female are unaffected (Carrier) 3.Homozygous female are affected 4.Affected female has affected father and a mother who is affected or a carrier 5.Father cannot pass to son 6.Carrier female has 50% chance to pass to sons

Sex Influenced traits

1.An allele is dominant in one sex, but recessive in the other sex 2.Can be X-linked or autosomal (but tend to be autosomal) Example: baldness ( gene for pattern & gene for testosterone production)

Criteria for x-linked dominant traits

1.Females only need 1 copy to express 2.Usually very severe in males 3.Affected father passes to all daughters 4.Affected father cannot pass to sons 5.Affected mother has a 50% chance to pass on to her daughters and sons

2 types of Genetic drift

1.Founders effect (Tahiti) -18 sailors left, married, 9 left to island, ¼ have migraine disease 2.Population bottleneck (Micronesia) - Typhoon killed all but 9 + 10, 10% have eye condition

Signs of positive selection

1.Gene varies very little from person to person 2.Gene found in other organisms with only single amino acid change

Sex limited traits:

1.Genes that are present in both sexes, but only expressed in one, "turned off" in the other. 2.The two sexes show different phenotype even though they have the same genotype 3.Can be X-linked or autosomal Example: beard growth(hormone not in women, but can pass gene to son)

Factors that shape populations at the allele level

1.Nonrandom/selecive mating 2.Migration 3.Genetic Drift 4.Mutations 5.Natural selection

Single gene inheritance is rare. Genes interact with:

1.Other Genes 2.RNA that turns it on/off 3.Epigenetic alterations Environmental influences

Dihybrid Cross

2 different genes for 2 different traits

Mendelian Ratios

3:1 or 9:3:3:1

-Autosomal recessive trait (short middle finger) -If you know frequency dominant and recessive alleles = calc frequency of genotypes and phenotypes - 9 of 100 people have short (dd) fingers

9/100 = 0.09 frequency dd = q2 solve for q √dd = √ .09 = q = 0.3 Know p + q = 1 p + 0.3 = 1 p = 0.7 DD = p2 = 0.7 = 0.49 so 49% homozygous dom dd = q2 = 0.3 = 0.09 so 9% homozygous rec Dd + dD = 2pq = (0.7)(0.3) + (0.3)(0.7) = 0.42 so 42% heterozygous

Modes of Inheritance (MOI): Can be:

:Pattern a gene variant passes from generation to generation •Can be: 1.Dominant MOI 2.Recessive MOI 3.Autosomal MOI 4.Sex Linked MOI 5.Mitochondrial MOI

•Negative selection •Positive selection •Artificial selection

= getting rid of a trait = keeping a trait = controlled breeding

MOI - Autosomal Dominant Criteria for autosomal dominant traits:

Affects both males and females & male to male transmission is possible 2. Males & females transmit with equal frequency 3. Does not skip a generation 4. Transmission stops after generation where no one is affected Huntington's Disease : Neurodegenerative, symptoms in 20's, death within 15 years, always fatal

How penetrance and expressivity work together:

All of the individuals have the same mutant phenotype. All of the individuals have different mutant phenotypes. Some of the individuals have the same mutant phenotype. Some of the individuals have different mutant phenotype.

Test Cross

Cross individual with unknown genotype with a homozygous recessive individual

Law of Segregation: 4 Main principles of the Law of segregation:

During gamete production, 2 copies of each hereditary factor segregate so that offspring acquire 1 factor from each parent 1.A gene can exist in more than one form (allele) 2.Organisms inherit 2 alleles for each trait 3.When gametes are made (meiosis) allele pairs separate so that each cell has a single allele for each trait 4.When 2 allele pairs are different, one is dominant and the other is recessive

Cystic Fibrosis example

F508 most common allele for CF: WT/WT = no CF WT/ F508 = carrier F508/ F508 = CF Allele frequency = includes all three

Crossover and independent assortment also do this, but they only add ___________________ rather than introduce _______________________ does.

Genetic variability new ones as mutation •Includes: 1.DNA base changes 2.Copy number variant repeats

Epigenetic Alterations

Includes: 1- DNA methylation 2- Chromatin remodeling 3- Histone modifications •The genome is identical in all your cell types •Your epigenome is different in different cell types at different times

MOI - Autosomal Recessive Criteria for Autosomal recessive traits:

Males and females can be affected 2. Affected males & females can transmit the trait unless the trait causes death before reproductive age 3. can skip generations 4. Affected person's parents are either heterozygous or have the trait Cystic Fibrosis: 1950's 10yo, 2007 37yo die of respiratory infections Consanguinity : marriage between relatives increases chances - Qatar, ½ of all marriages between 1st cousins

Mt DNA vs. Nuclear DNA

Mt DNA: No crossover, Very little repair mech, Inherited form mom, No histones, circular, More mutations, Many copies per cell, haploid, No introns Nuclear DNA: Crossover, Numerous repair mech, Inherited from mom and dad, Many histones, linear, fewer mutations, 1 copy per cell, diploid, introns

Genetic equilibrium is when allele frequencies are ____________ and is _______________

Not changing rare

old and new ways of studying multifactorial traits:

Old: •Empiric risk •Heritability •Adoption studies •Twin studies New: -Genome wide association studies

Phenotypic frequency

Percentage of people in the population who have CF

Product Rule

Predicts the chance that parents with known genotypes can produce offspring of a particular genotype.

Genotypic frequency

Proportion of heterozygotes & homozygotes in the population

Twins vs. Adoption studies

Twins •Great tools, but differ in CNV •Monozygotic identical vs. Dizygotic fraternal •Concordance = % of pairs which both twins express trait •University of Minnesota Twin Conference Adoption studies •Share Environment with adopted parents, but not genes •Share genes with biological parents, but not environment •Denmark study on cause of Death - biological parent died of infection, biological child 5x more likely - adoptive parent died of cardiovascular disease, adopted child 3x more likely

DNA Profiling: -Do not affect phenotype -Are in Hardy Weinberg Equilibrium -Can identify individuals

VNTR - widely used, any nucleated cell STR - When DNA fragmented (explosions, disasters) mtDNA - When chromosomal DNA is too degraded •Forensics •World Trade Center •Natural Disaster •Holocaust Survivors DNA mixtures

Hardy-Weinberg equilibrium

When allele frequencies become constant. p = Dominant allele q = Recessive allele p+q = 1 p^2 + 2pq + q^2 = 1.0

Changing __________ frequencies change _________________ frequencies that in turn change _______________ frequencies

allele, genotypic, phenotypic

Genetic Drift

change in allele frequency due to small groups being separated from larger group

Mutation

changes one allele to another which is passed on to offspring

Eugenics

control of Individual reproductive choices to achieve societal goals

Microevolution

is a small change of allele frequency in a population

Allele frequency

is how often a particular Population occurs in a particular gene variant

Macroevolution

is the result of many microevolution events

Gene pools are very fluid

limited Hardy Weinberg Equilibrium genes

Prenatal development

•5th week = All embryos develop 2 unspecialized gonads, eventually become either the testes or ovaries •6th week = SRY gene activates to steer hormone development •9th week = Gender differences become apparent Ultrasound = 18-20 weeks Amniocentesis = 16 weeks Fetal DNA/maternal blood = 7-10 weeks

Pleiotrophy

•A single gene disorder (mutation) that causes several Phenotypic changes •Very hard to trace in families •Ex. Porphyrias = porphyrins (heme like)

Penetrance

•All or non expression of a genotype •complete penetrance = allele combination that produces a phenotype in everyone who inherits it (very rare) - Ex. Huntington's disease •Incomplete penetrance = some individuals do not express the phenotype, usually described numerically - If 80 of 100 people show the phenotype = 80% penetrance - Ex. Mutation in BRAC1 & 2 genes

Phenocopy

•An Environmentally caused phenotype that appears to be inherited genetically •Occurs when: 1.Environmental factors produce symptoms that resemble those in single gene disorders 2.Environmental factors mimic Inheritance patterns by affecting certain relatives Ex. Thalidomide & phocomelia

Lethal Alleles

•An allele combination that causes death, usually denotes an essential gene •Can cause death at any age (Tay-Sachs = age 3, Huntington's = age 40+) •May cause death before reproductive age, thus preventing passage to the next generation •Can be dominant or recessive - Homozygous recessive = Harlequin ichthyosis - Homozygous dominant = Achondroplastic dwarfism •Other forms of lethal alleles 1.Conditional = death only happens under certain conditions (Favism disease) 2.Sub-lethal = cause death in some of the individuals with the genotype (hemophilia) 3.Synthetic = combination of 2+ alleles leads to death, but mutation in only one does not

Epigenetics - Transmission

•Can be passed from cell to cell- during cell replication •Can be passed parent to offspring- smoking causes methylation. Study: Grandmother who smokes alters epigenome à passed on in gametes à causes abnormal hormones à grandchild obesity •Can also be reprogrammed - methyl groups added during your lifetime to your DNA, during gamete formation go thru two cycles of demethylation, stripping the methyl groups off

Sexual development

•Conception = Baby's sex is determined at time of fertilization (XX or XY), but physical anatomy doesn't fully develop until around the 4th month of pregnancy

Epigenetics - How it effects cloning

•Despite advances & media accounts, mammals are really hard to clone •Normal cloning procedure 1.Take donor nucleus from Non-reproductive cell (skin cell) 2.Place into egg cell that has No nucleus •Clones have abnormal epigenomes 1.Donor nucleus comes from Differentiated cell= epigenetic tags already in place 2.Donor nucleus copying machinery sloppy = miscopies of epigenetic tags

Studying Multifactorial traits - Empiric Risk (Old)

•Empiric risk - probability that a trait will occur based upon its incidence in a population •Based on 1. Incidence = rate at which a certain event occurs (# of new cases diagnosed per year in a given population. 2. Prevalence = # of individuals in a population who have a disorder at a specific time •Is a population statistic based on observation, not a calculation •Can be broad (ex. Ethnic group) or specific (families with CF) •Increases with 1. Number of affected family members 2. How closely related you are to an affected family member 3. Severityof the disorder

Population Genetics

•Families & individuals we examine DNA sequences •At the population level we examine Allele frequencies •A population is any group/member of the same species in a given Geographical area that can mate and produce fertile offspring •Population genetics is a branch of genetics that examines all of the Alleles in a population •The gene pool is all of the alleles of a population •Gene flow is the movement of alleles between populations when individuals Migrate and mate

Studying multifactorial traits - GWAS (new)

•Genome Wide Association Studies •Older techniques looked for known gene variants in a few people, •GWAS looks for "signposts" (markers) in many people for common gene variants •GWS look at observable traits like BP, weight, presence/absence of disease •Limitations 1. Reveal associations not causes 2. Sample population Biases (clinics: only see affected, not those that died) 3. Misses rare individuals 4. Can lead to False positives (atherosclerosis - mutation or infection/smoking/exercise/diet)

x-linked traits

•Have different expression patterns in females vs. males •In females, X-linked traits are passed on like autosomal traits •In males, single copy of X trait causes trait or disease expression •Can have X-linked recessive traits or X-linked dominant traits •Males are considered hemizygous for X-linked traits

Studying multifactorial traits - Heritability (old)

•Heritability - an estimate of the amount of phenotypic variation that is due to genes •Different from empiric risk 1. Heritability is a calculation, empiric risk is not 2. Heritability focuses on genes empiric risk considers genes + environment •Heritability changes as the environment changes •Heritability equals 1 if a trait's variability is completely genetic •Use the coefficient of relatedness to calculate = proportion of genes 2 related people share

Epigenetics

•Heritable changes in Gene expression •Do not change the DNA sequence •Changes the phenotype without changing the genotype •Epigenome pattern of epigenetic modification present in a cell at a given time period

Epigenetics - Not just in humans

•Honeybees = Queen bees & worker bees have very different body types •Mice = methylated gene in brown fur mice, same gene unmethylated yellow fur mice •Ligers = male lion + female tiger (very big) •Tigon = male tiger + female lion (small)

Continuously Varying Multifactorial traits - Height

•How do we get our height 1. 70% Genetics - about 50 different genes suggested ( localized to chromosomes 7,8,20, X) Don't know why difference between males and females 2. 30% Environmental - availability of nutrients Genetic potential - developed vs non-developed

Continuously Varying Multifactorial traits - skin color

•How do we get our skin color -Genetics •100 different genes identified for skin, hair, iris •Melanocytes à Melanosomes à Melanin •Different combinations create different colors -Environment (past) •Melanin is a natural sunscreen •UV strips away folic acid, but makes Vitamin D •Migration of people required a delicate balance

X-linked recessive

•Ichthyosis -Mutated steroid sulfatase enzyme -Cholesterol cannot be removed properly -Top layer of skin cannot peel off, brown & scaly •Red-Green Colorblindness -6% of the population -Mutation or absence of retinal photoreceptors •Haemophilia B "Christmas Disease" -Impaired clotting factor IX gene -Excessive bleeding after injury, spontaneous bleeding, bleeding into joints -Treatment: IV infusions of clotting factors

x-linked dominant

•Incontinentia pigmenti -Lethal in almost all males -Females have red patchy pigmentation -NEMO gene mutated -Activates immune system -Affects cells of ectoderm (skin, hair, nails) •Congenital generalized hypertrichosis "Werewolf syndrome" -Produces extra hair follicles -Males covered in excess hair -Females mild asymmetric hair growth

genomic imprinting

•Is a form of epigenetics, but affects less than 1% of genes in the genome (~200 genes so far) •Imprinting process 1.During gametogenesis imprint is determined 2.Maintaining imprint during embryogenesis & adult somatic cells 3.Erasing the imprint in germ cells (reset)

Single gene: Polygenic: Multifactorial:

•Mendelian inheritance - one gene = one trait -Very rare(almost nonexistent in humans) •trait due to more than one gene -Rare (most are also multifactorial) •trait determined by several genes & the environment - follow Mendel's law (but harder to predict) - can be single gene or polygenic -Most common -Example, lung cancer

Mitochondria:

•Mitochondrial DNA (mtDNA) is maternally inherited •Only contains 37 genes (24 RNA molecules, 13 proteins) •Mitochondrial myopathy encephalopathy lactic acidosis syndrome (MELAS) •Powerful tool for science: forensics, wars, historical records

Genetic Heterogenicity

•Mutation in different genes that produce the Same phenotype •Occurs when 1.Genes encode enzymes that catalyze the same biochemical pathway 2.Genes encode different proteins that are part of the same pathway Ex. Osteogenesis Imperfecta vs child abuse

Phenotypic Forms

•Normal SRY pathway progression •SRY is a Transcription factor •Prenatal development a multistep process 1. SRY becomes activated 2. This causes female structures to degenerate 3. This also causes the activation of testosterone and DHT 4. Testosterone leads to the development of internal male structures 5. Dihydrotestosterone leads to development of external male structures

X-Inactivation

•One X chromosome is randomly inactivated in early embryonic cells, with fixed inactivation in all descendant cells •X inactivation center= responsible for silencing the X chromosome, only expressed on the inactivated X •XIST = gene critical for X inactivation, encodes a long RNA molecule that coats chromosome of gene that created it •Barr Body= the inactivated X chromosome, during interphase it stains darker •Effect on phenotype: 1.Homozygous X-linked = no effect 2.Heterozygous X-linked = express one cell or the other (mosaic) 3.X -inactivated cell can be helped by mosaic cells (Hunter Syndrome)

Compound Heterozygote

•Person has 2 different alleles, each with a Different mutation •Can sometimes predict the course of a disease: Phenylketonuria (PKU) - lack enzyme to break down phenylalanine, Depending on the allele and mutations can be: 1. classic PKU - profound intellectual disability 2. moderate PKU - moderate intellectual disability 3. mild PKU - mild intellectual disability 4. asymptomatic PKU - body gets rid of phenylalanine

Histone Modifications

•Post translational modification of amino acids near the N-terminal ends •N-terminal end actually has a tail exposed •Methylation = closed, inhibits transcription •Acetylation = relaxed, open for transcription •Writers - Readers - Eraser proteins (enzymes)

Polygenic traits are continuously varying:

•Quantitative trait loci (QTL) -Quantitative trait = measureable trait -Loci = location -Mapping genes that contribute to polygenic traits •Individual genes of a polygenic trait (how they contribute) . Follow Mendel's law, but together do not make typical phenotypic ratios 2. All contribute to the phenotype 3. Are not dominant/recessive to each other 4. When plotted usually form a bell curve

Y-linked

•Rare •Considered Hemizygous •Retinitis Pigmentosa -Rods die off -Cones lose function -Tunnel vision •Infertility

Y-linked traits

•Rare because 1)So few genes on the Y-chromosome 2)So many counterpart genes on the X-chromosome

Sex ratio

•Sex ratio = proportion of males to females in a population (#males / #females) x 1000 •Males = Females = 1000 If more males > 1000, if more females < 1000 •Primary sex ratios Ratio at conception, favors males slightly •Secondary sex ratios Ratio at birth •Tertiary sex ratios At maturity, favors females •Society & sex ratio Different cultures/societies favor different proportions - 117 males for every 110 females, by 2020 = 20 million men without female partner

What causes epigenetics?

•Smoking = alters methylation & histone modification in lung cells •Bisphenol A (BPA) = changes methylation in utero, predisposition to cancer •THC = exposure during adolescence, future offspring predisposed to heroin addiction •Famine = maternal starvation can pass through 3 generations, offspring more likely to have cardiovascular problems & diabetes, less methylation on insulin growth factor •Nurturing= pups high nurtured became calm adults & nurturing to their pups, pups with no nurturing had anxiety & would not nurture their pups •Cancer - first disease to be linked to epigenetics, can now be used as biomarker for molecular diagnosis of early cancer •Autoimmune disease - Lupus, T-cells have decreased methylation •Gestational diabetes = pregnancy induced diabetes fetus exposed to high levels of glucose, epigenetic changes to fetus = more likely to have gestational diabetes •Childhood abuse = changes methylation, future poor health •Exercise = changes methylation in muscle & fatty tissue

Continuously Varying Multifactorial traits - Fingerprints

•Static = always have the same throughout life (nobody's are the same) •Structure : Arches, Loops, Whorls = can have 1, 2 , or all 3 •How do we get them? Hint: Identical twins do not have the same 1. Genes = Pattern types are inherited 2. Environment = finger pads + amniotic sac, individual difference are not inherited •Total Ridge Count & syndromes # if whorls, loops, arches (men=145, Females = 126) Klinefelter's Syndrome lots of arches on 1st finger Naegeli Syndrome no fingerprints Dermatoglyphics = scientific study of fingerprints

Expressivity

•The Severity or extent of the trait or mutation •Varies in intensity among different people •Ex. Polydactyly

Linkage

•The transmission of genes on the same chromosome •These genes DO NOT: 1.Assort independently 2.Produce Medelian ratios •Linkage is disrupted by crossover •This disruption is more likely between genes that have Greater distances from each other

Sex Chromosomes - the founder

•What was previously thought (1900's) 1.Temperature of the father 2.Nutrition of the mother 3.Right vs Left side 4.Specific testes and ovaries • Who changed it all = Nettie Stevens Mealworms Females had large chromosomes Males had large and small chromosomes Her boss got the credit

Law of Independent Assortment

•When 2 or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together.

Epistasis

•When one gene Masks the phenotype of an entirely different gene •Is the interaction between different genes, not the alleles of the same gene •The gene that affects expression of another gene is called the Modifier gene •The blocked gene is expressed normally, but the product of the modifier gene Inactivates it •Example: Spinal muscular atrophy vs plastin 3 gene

Atypical sex chromosomes : Aneuploid females

•XO Syndrome (45, X) aka turner syndrome -Only one X chromosome -99% of fetuses do not survive -1:3,000 births -Abnormal growth, short, sterile -Linda Hunt •Triplo X Syndrome (47, XXX) aka Trisomy X -Have three X chromosomes -Not as many symptoms (due to X-inactivation) -1:1,000 births (~5-10 born in US-a-day)

Atypical sex chromosomes : Aneuploid males

•XXY Syndrome (47, XXY) aka Klinefelter's Syndrome -Extra X chromosome -Men may develop breast tissue, reduced testosterone -1:600 births •XXYY Syndrome (48, XXYY) -Extra X and Y chromosomes -Infertility, behavior & medical problems -1:18,000 births •XYY Syndrome (47, XYY) -Extra Y chromosome -Normal features & fertility -Not as severe because less genetic content on Y 1:1000 male births

Multiple Alleles

•You have 2 alleles for any autosomal gene, one on each homolog •Each gene can exist in more than 2 Allelic forms in a population •Produces variations in phenotype, more alleles = more phenotypes •Example human ABO blood type There are 3 alleles for blood type (IA, IB, i) There are 6 possible genotypes for blood type There are 4 possible phenotypes for blood type

Natural selection

•allele frequencies altered because survival and reproduction of individuals with a particular Phenotype in a particular environment are more favorable

Cline

•allele frequencies that change from one geographical area to another. 1.Gradual changes - 2.Physical barriers - Example: Nile River

Punnett square- Homozygous- Heterozygous- Genotypic ratios- Phenotypic ratios-

•diagram that maps out possible genotypic/phenotypic outcomes of different allele combinations •Homozygous = 2 identical alleles for a particular trait (can be dominant or recessive) •Heterozygous = 2 different alleles for a particular trait (one is dominant & one is recessive) •Genotypic ratios. 1 (TT) : 2 (Tt) : 1 (tt) vs •Phenotypic ratios. 3 Tall (TT, Tt, Tt,) : 1 short (tt)

Nonrandom mating

•mating that has not occurred due to chance and have had Human interference •80%, 1/3 in 10 miles •Occurs when certain individuals contribute more to the Next generation than others Examples: Cape Town - 20yo, 7 wives, 356 descendants, teeth Gheghis Khan - 1 in 200 males share his Y (AR-CHN) Consanguinity - marriage of family members

DNA methylation

•methylome = set of methylated nucleotides in your genome at given time -Cell & tissue specific -Is not fixed, changes -Happens after DNA replication -Happens during cell differentiation -Adds CH3 to cytosine -Methyltransferase performs this -Mostly clustered around CG dinucleotides (CpG islands) near promoters

Blood type is determined by:

•pattern of molecules on RBC •A & B co-dominant (thus the AB bloodtype) •A is dominant to O •B is dominant to O

Heteroplasmy- Homoplasmy-

•some mitochondria have the mutation, some do not •all mitochondria are either wild-type or mutant

Sex linked traits

•what we have been talking about so far. Genes associated with a particular Sex chromosome(ex. X-linked and Y-linked traits).

Migration

•when a population picks up new individuals that Add or remove alleles from the population •Example: NYC