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Cross Pollination
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A reproductive process in which pollen from one plant is transferred to the stigma of another plant, in order to insure that he could control what he was planting he removed the stamens of a plant before they reproduced pollen and then dusted pollen from another plant onto altered flowers stigma.
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Two characters
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Allowed Mendel to derive the law of independent assortment ( like flower color , and seed shape)
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Genotype
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an organism's genetic makeup, or allele combinations
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Gregor Mendel
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Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822-1884)
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Albinism
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A hereditary condition characterized by a partial or total lack of melanin pigment (particularly in the eyes, skin, and hair), caused by a reccesive allele.
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Testcross
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a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring
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Genes
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One of the main parts of Mendels theory surrounding the law of segregation, alternative versions of _______ account for variations in inherited characteristics. The alternative versions of this are called alleles.
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Complete Dominance
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A type of inheritance in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
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Single Character
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One of the things that allowed mendel to derive the law of independent assortment, such as flower character.
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Quantative Characters
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This usually indicates polygenic inheiritance (additive effect of two or more genes on a single phenotypic character), Where the characters in a population vary along a continium. (Height, Skin Color)
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Phenotype
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what an organism looks like as a consequence of its genotype
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Multifactorial
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Many factors, both genetic and environmental, collectively influence phenotype. Like Quantative just more enviromental.
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Malaria
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vectored disease spread by mosquitoes that carry the malaria parasite in their saliva and which kills approximately 150,000 children in the global periphery each month, reason why sickle cell disease is so common in African Descent.
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Dominant
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Describes a trait that covers over, or dominates, another form of that trait (In Mendel's case Purple)
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Chronic Villus Sampling
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A technique of prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed and analyzed to detect certain genetic and congenital defects in the fetus
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Pleiotropy
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The control of more than one phenotypic characteristic by a single gene, are responsible for the large range of symptoms in diseases such as cystic fibrosis and sickle cell disease.
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Carriers
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individuals who have one copy of a recessive autosomal allele, have to be heterozygous(if fatal), but don't if it is not.
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Cystic fibrosis
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A human genetic disorder caused by a recessive allele for a chloride(Cl-) channel protein; characterized by an excessive secretion of mucus and consquent vulnerability to infection; fatal if untreated (4% whites are carriers - most common lethal genetic disease), Pleiotropic
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Christian Doppler
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Austrian mathematician and physicist who observed that the apparent change in frequency and wavelength of a wave as perceived by an observer moving relative to the wave's source. Also instilled in Gregor Mendel a sense of mathematics to prove his science.
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Particulate Hypothesis
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Also called the "Gene Idea", in this model parents pass on discrete heritable units that retain their separate identities in offspring, proven by Gregor Mendel.
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Phenotype
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what an organism looks like as a consequence of its genotype
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Punnet Square
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A chart that shows all the possible combinations of alleles that can result from a genetic cross.
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Tay Sachs Disease
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A human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth. At the organismal level it is recessive, lipid metabolizing level(biochemical) it is intermediate(incomplete dominance), and at the molecular level(production of enzyme) they are (codominant)
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Recessive
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One of the main parts of Mendels theory surrounding the law of segregation, if the two allelles at a locus differ, then one , the dominant allele, determined the organisms appearance, the other ________ allele has no noticeable effect
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Spectrum of Dominance
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Spectrum of alleles show different degrees of dominance and recessiveness in relation to each other phenotype
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Alleles
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One of the main parts of Mendels theory surrounding the law of segregation, for each character, an organism inherits 2 ________, one from each parent. Mendel made this deduction without knowing about the role of chromosomes.
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Character
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A heritable feature, like color that varies among individuals.
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Polydactyly
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A congenital anomaly caused by a DOMINANT allele characterized by the presence of more than the normal number of fingers or toes. 1 in every 400 have it.
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Unaffected
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The outcome of another event happening(probability) is __________ by a specific result in Mednelian Genetics.
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True Breeding
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Term used to describe organisms that produce offspring identical to themselves if allowed to self-pollinate.
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Karyotype
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Set of photographs of chromosomes grouped in order in pairs
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Amniocentesis
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A technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from needle inserted into the uterus(between 14-16), is analyzed to detect certain genetic and congenital defects in the fetus, such as Tay Sachs, results will be karyotyped. Another method is chronic villus sampling (cvs)
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Purple
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The color of the pea plants that were dominant in his F1(all individuals) and in the F2 generation with 3/4 of the individuals.
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Heterozygous
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Term that describes having dissimilar alleles at corresponding chromosomal loci (not true breeding)
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Law of Independent Assortment
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States that for each pair of alleles segregate independently of each other pairs of allelesduring gamete formation.(Applies only to genes(allele pairs) located on different chromosmes(that are not homologus.
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Widows Peak
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Controlled by a dominant allele (W). Those with homozygous for the w allele possess a straight hairline
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Incomplete Dominance
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a condition in which a trait in an individual is intermediate between the phenotype of the individual's two parents because the dominant allele is unable to express itself fully
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Recessive
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A trait that is masked by by the presence of a dominant trait( In Mendels case White)
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F1 generation
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The first generation of offspring obtained from an experimental cross of two organisms (P generation) (Now all non-true breeding, heterozygotes)
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Pleion
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Greek for more, many
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Hybridization
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The mating of 2 true breeding varities, and the first generation is refered to as the P generation.
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Epistasis
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Greek word meaning stopping, where a gene at one locus alters the phenotypic expression of a gene at a second locus, is the converse of polygenic inheiritence
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Level
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For any character the observed dominance/ recessivness relationship of alleles depends on the _________ that we examine phenotype. For Example Tay-Sachs: at the oranismal level it is recessive, at the molecular codominant, and at the biochemcal( incomplete dominance)
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Achondroplasia
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A form of human dwarfism caused by a single dominant allele; the homozygous and heterozygous condition is lethal, means that 99.99 % of people are homozgous recessive for the allele.
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Law of Segregation
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The two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes
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Norm of Reaction
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The range of phenotypes produced by a single genotype, due to environmental influences.
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Genotype
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the genetic makeup of an organism
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Codominance
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situation in which both alleles of a gene contribute to the phenotype of the organism
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Heterozgote Advantage
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Occurs when individuals who are heterozygous at a particular gene locus have a greater fitness than the homozgotes. ( Hemoglobin in Sickle Cell Disease). Aggregate benefit balance aggregate harm of the allele.
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Trait
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Each variant of a character, For Example : Character = color. This would equal red , white ,blue.
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Sickle Cell Disease
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A recessive disorder, sickle shaped cell form when there is a low amount of oxygen, can't carry oxygen and can clog blood vessels, can cause many problems including paralysis, also like cystic fibrosis it is pleitropic.
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White
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The color of the pea plants that were reccesive in f1(0/4 individuals), and in the F2 generation(1/4 individuals)
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Dihybrids
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individuals heterozygous for two characters
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F2 Generation
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The second generation of offspring, obtained from an experimental cross of two organisms; the offspring of the F1 generation, this is the generation that allowed Mendel to figure out the laws of genetics.
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Pedigree
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a diagram that shows the occurrence of a genetic trait in several generations of a family
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Alleles
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one of a number of different forms of a gene.
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Multiplication Rule
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The rule that states that to determine the probability, we multiply the probability of one event by the probability of another
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Schizophrenia
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A group of severe disorders characterized by disorganized and delusional thinking, disturbed perceptions, and inappropriate emotions and actions. Is an example of a disease that is mutlifactorial.
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Addition Rule
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What probability rule states that any one of two or more mutually exclusive events will occur is calculated by adding together their individual probabilities
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Blending Hypothesis
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The idea that genetic material contributed "mix" together in a way that blue + yellow make green. Predicts that over many generations a freely mating population would give rise to a uniform population of individuals. Fails to explain how some traits reappear after skipping a generation. Disproved by Gregor Mendel.
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Monohybrid
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a hybrid produced by crossing parents that are homozygous except for a single gene locus that has two alleles (as in Mendel's experiments with garden peas)
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Homozygous
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Term that describes having identical alleles at corresponding chromosomal loci
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Huntington's Disease
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A human genetic disease caused by a dominant allele(near chromosome 4); characterized by uncontrollable body movements and degeneration (which is both irreversible and fatal) of the nervous system; usually fatal 10 to 20 years after the onset of symptoms. 50 % chance of getting the disorder
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Polygenic inheritance
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Process by which several genes interact to produce a certain trait; responsible for most important traits like skin color, eye color, height , CONVERSE of pleitropic. Aids in the development of quantative characters. BELL CURVE on pg. 263 look at it. Enviromental factor like sun exposure would make the bell curve smoother. Has the broadest norm of reaction.
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Large Sample Size
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One of the things that Mendel had that made his experiment a success. A total of about 1000 individuals in the F2 generation.
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Consanguineous
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A term meaning descended from the same parent or ancestor, increases the chance of harmfeul reccesive alleles being passed down. Indicated by a double line in a pedigree.
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P generation
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Parental generation, the first two individuals that mate in a genetic cross
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