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1. Who is named the “Father of Genetics?” Gregor Mendel 2. Why did he use pea plants? To study the inheritance of traits
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What do pure bred, true breeding, and homozygous mean? All mean the same thing… Both alleles are either capitals or lower case. AA or aa
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What do hybrid and heterozygous mean? Actually mean the same thing… A a 2 Alleles are different
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All HYBRID (Gg) offspring result What type of offspring results when you cross two pure “true” breeding parents with different traits?
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Understand which is the P, F1, F2 generations and how you get each.
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Genotype Ratio: 1 RR: 2 Rr: 1 rr Phenotype Ratio: 3 Round: 1 Wrinkled Tt TTTTt t tt What results when the offspring Tt (F1) of true breeding parents self-pollinate (breed with themselves)? Tt x Tt
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Probability= The chance of something happening! Chance of getting heads ½ or 50%
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More times you flip a penny, the more likely you are to get the “expected” outcome (probability). ½ heads, ½ tails
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½ x ½ x ½ x ½ x ½ x ½ 1/64 If you toss a coin 6 times in a row, what is the probability it will land heads for all 6 tosses?
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During gamete formation, genes for different traits separate without influencing the other. “Law of Independent Assortment” Foil each parent to get 4 gametes G g Y y GY Gy gY gy
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Complete Dominance The dominant trait (G) masks (hides) the recessive trait (g) and only the dominant trait shows up in the phenotype. Incomplete Dominance Neither trait is dominant over the other and a new trait is displayed. BLENDING!!! Red flowers crossed with white flowers make pink flowers. Co-Dominance Both traits are equally displayed and neither is dominant over the other. ABO blood types: A blood x B blood = AB blood
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What are polygenic traits? Traits that have a wide variety of color ranges such as eye colors, hair color, skin color and height.
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GenotypeIAIA or IAiIBIB or IbiIAIBii PhenotypeA BloodB BloodAB BloodO Blood
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Describe the genotypes and phenotypes of each blood type: AB has same Genotype & Phenotype Co-Dominance
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First determine how many different letters are there for each letter type then multiply ! A A B b C c D d E E F F G g H h 1 x 2 x 2 x 2 x 1 x 1 x 2 x 2 = 32 gametes How many different gametes?
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Can this parent AaBBccDdeeFfGgHH have a child with the following genotype? Why or why not? NO, because the parent would need to have a big E in their genotype in order for the child to have both big E’s. A A B b C c D d E E F F G g H h
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What is this picture called? Karyotype
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What is this called? Karyotype Shows: Autosomes = all chromosomes # 1 - 22 chromosome pairs (not sex chromosomes) Sex Chromosomes XX= female or XY= male (# 23 pair) Homologous Chromosomes = chromosomes that code for the same traits and pair up with each other Inherited Disorders (ex: Down’s, Turner’s, Kleinfelter’s, Super males/Super females)
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What are the chromosome pairs for a … FEMALE MALE XX XY
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Non-disjunction –When chromosome pairs don’t separate properly during Meiosis I Can involve all chromosomes (sex, autosomes, homologous)
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Down’s Syndrome (Trisomy 21)
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XXY Kleinfelter’s Syndrome
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XO Turner’s Syndrome
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Super Female
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Super Male XYY
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Father determines sex of offspring Father provides either an X or a Y to pair up with the mother’s X to make a boy or girl 50% chance of Boy XY 50% chance of Girl XX
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Know the term Sex-linked genes/traits and how the key and Punnett square would look. What chromosome carries these types of traits? XBXb XBXbXbXb YXBYXbY XBXb x XbY Carrier Female x Male Colorblind Phenotypes: 1 Female/Carrier 1 Female/Colorblind 1 Male/Normal 1 Male/Colorblind Sex-linked traits only carried on X Y doesn’t carry traits! Sex-linked gene/trait – Traits linked to sex chromosomes such as hemophilia or colorblindness
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Pedigree Chart Shows how a trait is passed from one generation to the next Shows male or female Shows “no trait” “carries trait” or “has trait” 4 Generations shown Normal Male Normal Female Female with Trait Carrier Female Male with Trait Line = Marriage
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REMEMBER: IN SEX-LINKED PEDIGREES, MALES CANNOT BE CARRIERS OF THE TRAIT. THEY EITHER HAVE IT OR NOT.
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Dominant- Trait is one that can mask (hide) the recessive trait Recessive- Trait that gets masked (hidden) by the dominant trait Punnett Square- Tool to determine possible outcomes (probability) Homozygous- When both alleles look the same (AA or aa) Heterozygous – When both alleles do not look the same (Aa) Phenotype – The “physical” appearance (tall, short) Genotype – Allele letters (Aa, TT, tt)
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Allele- Different forms of a gene Gametes- Sex Cells (egg & sperm) Gene- Part of a chromosome; codes for a trait Genetics- Study of how traits are passed generation to generation Karyotype- Picture of all paired chromosomes - looking for sex and the presence of abnormal # of chromosomes Pedigree- Chart that shows passing of trait from one generation to the next generation Probability - Chance of something happening Punnett Square- Chart showing possible offspring from a parent cross.
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Co-dominance – Both alleles expressed EQUALLY Incomplete dominance – Blending of traits Diploid – Having 2 sets of chromosomes Haploid – Having 1 set of chromosomes Independent Assortment – Genes that separate have no effect on the other’s inheritance Non-disjunction – When chromosomes don’t separate Segregation – Separation of alleles during gamete formation Multiple Alleles – 2 or more genes code for a trait Polygenic Traits – Many genes working together to give a trait such as eye color or height
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Know how to do the following types of crosses: Monohybrid Cross Dihybrid Cross Incomplete Dominance Cross Sex-linked Cross Must show: key, parents’ genotypes, possible gametes, Punnett square, genotypes and phenotypes of offspring
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