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Anna MontgomeryBio 109 Test Final NotesChapter Nine – GeneticsTesting Your Baby- Genetic testing- Allows expectant parents to test for possibilities in their unborn child- Includes amniocentesis and CVS- Has risks associated with itGregor Mendel- Was the first person to analyze patterns of inheritance- Deduced the fundamental principles of genetics- Mendel studied garden (sweet peas)- These plants are easily manipulated- These plants can self fertilizeo Girl part of the plant is the carpelo Male part of the plant is the stamen (pollen)o Can self fertilize or be carried by wind or bees (cross - Four characteristics of good genetic model organism: (KNOW FOR TEST)o Readily availableo Easily manipulatedo Cost effective o Short generation kind- He created true breeding varieties of plants- Mendel then crossed two different true breeding varieties, creating hybrids- The offspring from these crosses are called the first filial or F1 generationMonohybrid Crosses- A monohybrid cross is a cross between parent plants that differ in only one characteristicMendel’s Four Hypotheses- There are alternative forms of genes, the units that determine heritable traits- For each inherited character, an organism inherits two alleles, one from each parent- If the two alleles of an inherited pair differ, the one determines the organism’s appearance and is called the dominant allele, theother has no noticeable effect on the organism’s appearance andis called the recessive allele- A sperm or egg carries only one allele for each inherited character because the two members of an allele pair separate from each other during the production of gametesGenetic Alleles and Homologous Chromosomes- Homologous chromosomeso Have genes at a specific locio Have allele of a gene at the same locuso See figure 9.7- Capital letters (PP) are homozygous for the dominant allele- Lowercase letters (aa) homozygous for the recessive allele- One of each (Bb) is heterozygous- Homozygous is when an organism has identical (same) alleles fora gene- Heterozygous is when an organism has different alleles for a gene- Phenotype is an organism has different alleles for a gene- Phenotype is an organism’s physical traits- Genotype is an organism’s genetic makeupo There should be two copies (alleles) of each gene - Mendel’s principle of independent assortment says each pair of alleles segregates independently of other pairs during gamete formationUsing a Testcross to Determine an Unknown Genotype- A testcross is a mating between:o An individual of unknown genotypeo A homozygous recessive individual - A family pedigreeo Shows the history of a trait in a familyo Allows researchers to analyze human traitsHuman Disorders Controlled by a Single Gene- Many human traitso Show simple inheritance patternso Are controlled by genes on autosomes (know what autosomes means)Recessive disorders- Most human genetic disorders are recessive- Individual can be carriers of these diseasesStarted class off with a worksheet that contains materials that will be on the final.Variation on Mendel’s Laws- Some patterns of genetic inheritance are not explained by Mendel’s principles- Incomplete Dominance in Plants and People:o In incomplete dominance, F1 generation hybrids have an appearance that is in between the phenotypes of the two parents- Hypercholesterolemia is a human trait that is incompletely dominantABO Blood Groups: An example of Multiple Allele and Codominance- Two of the human blood type alleles (A and B) exhibit codominanceo Both alleles are expressed in the phenotypeo Review blood typesPleiotropy and Sickle Cell Disease- Pleiotropy is the impact of a single gene on more than one characteristico Sickle cell disease is an examplePolygenetic Inheritance- A trait is controlled by two or more genesMultifactorial Disorders- Many diseases have a genetic component and a significant environmental componento Ex. heart disease, cancer, mental illness, asthma- Often, the hereditary component is poly genetico Ex. at least 15 known genetic loci which can have alleles that contribute to symptoms of asthmaSex Chromosomes and Sex Linked Genes- Sex chromosomes influence the inheritance of certain traits- Sex chromosomes are designated X and Y (men) and XX (women)- Sex chromosomes determine an individuals sexSex Linked Disorders in Humans- A number of human conditions result from sex linked (X-linked) genes- Red green color blindness is one exampleo It is characterized by a malfunction of light-sensitive cells in the eyesHemophilia- Hemophilia is a disease in which the blood does not clot properly- Red indicates the hemophilia alleleo Family tree: circle is woman and square is manMarch 31st, 2014Cellular Reproduction- Basic Concepts- Two types of cell reproduction processes in humanso Mitosiso Meiosis- Each body cell nucleus has 46 chromosomes (2N)o 23 from father and 23 from mother- For an organism to grow and develop, cells have to reproduce- So what happens when your skin epidermis cells produces new cells?- Goes through the cell cycle as it grows- Nucleus and cell divide= mitosisCell Cycle- First phase: interphaseo G1 Primary period of cell growtho S DNA is duplicated; growth continues slowlyo G2 Cell prepares for division; growth continues slowly- Mitosiso Nucleus divides- Cytokinesiso Cell divideso New daughter cells are formed; genetically identical to original cellMitosis Stages- Prophase Io Early mitotic spindles presento Chromosomes are presento Centrosomes can be seen- Prophase IIo Fragments of the nuclear envelope can be seeno Can see spindle microtubules- Metaphaseo Chromosomes align in the middle- Anaphaseo Daughter chromosomes split- Telophase/cytokinesiso Nuclear envelope formingo Cleavage furrow17.5 Environmental Factors Influence Cell Differentiation- All body cells have the same DNA, yet there are great differencesbetween the shape and function of different cell types- Toti-potent- Differentiationo Process by which a cell becomes different from its parent or sister cello Differentiation is based on different gene expression (genes are "turned on" or "turned off" at various stages of development)Meiosis: Preparing for Sexual Reproduction (Pg. 415)- In Meiosiso Haploid gametes are produced in diploid organismso Two consecutive division occur, meiosis I and meiosis II, preceded by interphaseo Crossing over occurs- Interphaseo Centrosomes (with centriole pairs)o Nuclear envelopeo Chromatin- Meiosis I- Homologous chromosomes

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UA BSC 109 - Test Final Notes

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