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Published byNigel Arnold Modified over 9 years ago
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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 do we call the offspring when you cross two pure “true” breeding parents with different traits?
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Offspring of two parents (P) are called ____. TT x tt “P” Generation 4 Tt “F1” Generation
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Genotype Ratio: 1 TT: 2 Tt: 1 tt Phenotype Ratio: 3 Tall: 1 short 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. 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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Describe the genotypes and phenotypes of each blood type: AB has same Genotype & Phenotype Co-Dominance
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What are polygenic traits? Traits that have a wide variety of color ranges such as eye color, hair color, skin color and height.
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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 process forms the sex cells (gametes) in females and males? Meiosis 4 Sperm are produced 1 Egg and 3 polar bodies are produced Female Male
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The paired, Homologous Chromosomes come together during Meiosis I to make Tetrads The chromatids pull apart during Meiosis I I 4 genetically different cells result at the end of Meiosis Haploid = one set of chromosomes Know the stages of Meiosis (I & II)
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When does crossing over occur during Meiosis? Prophase 1 Why is this important? Genetic Diversity
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What are the chromosome pairs for a … FEMALE MALE XX XY
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Karyotype
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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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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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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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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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MitosisMeiosis Somatic Cells – All body cells Sex Cells – Gametes (sperm and egg) 2 cells are made: Identical4 cells are made: All different Diploid “2N”Haploid “N” Asexual ReproductionSexual Reproduction Advantages No mate needed for reproduction Very fast reproduction time Lots of organisms Advantages GENETIC DIVERSITY! Disadvantages All organisms are alike, No Genetic Diversity Disadvantages Need a mate for reproduction Slower reproduction time Fewer organisms MUST KNOW ALL OF THIS INFORMATION!!!!! MITOSIS vs MEIOSIS
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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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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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Dominant – Gene whose effect masks the partner (recessive) trait Recessive – Gene whose effect is masked by partner (dominant) trait Genotype – Genetic makeup; gene type Phenotype – Trait expressed “physical” looks Heterozygous – Pair of different alleles (Rr) Homozygous – Pair of same kind of alleles (RR) (rr) Trait – Inherited characteristic (feature) Homologous – Pair of same kind of chromosomes
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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
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Understand which is the P, F1, F2 generations and how you get each.
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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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