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1. What does the word ambition mean to you? 2. What are the 3 components of a nucleotide?

1. What does the word ambition mean to you? 2. What are the 3 components of a nucleotide?. Recall. What is the purpose of mitosis? What is the purpose of meiosis?. Organismal Development Remember…. 1. A zygote is a _ 2. Cell Specialization is __

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1. What does the word ambition mean to you? 2. What are the 3 components of a nucleotide?

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  1. 1. What does the word ambition mean to you?2. What are the 3 components of a nucleotide? I can understand simple Mendelian genetic principles. I can work punnett squares.

  2. Recall • What is the purpose of mitosis? • What is the purpose of meiosis?

  3. Organismal Development Remember… • 1. A zygote is a _ • 2. Cell Specialization is __ • 3. As cells differentiate the body changes shape called: _ • 4. Apoptosis is critical in morphogenesis. I can understand simple Mendelian genetic principles. I can work punnett squares.

  4. Cloning • 1. Take haploid egg out of female. • 2. Remove haploid nucleus, implant diploid nucleus of desired organism. • 3. Place egg in surrogate (recipient ). • Dolly 1997 I can understand simple Mendelian genetic principles. I can work punnett squares.

  5. Mammary cell donor Egg cell donor Egg cell from ovary Nucleus removed Cells fused Cultured mammary cells are semistarved, arresting the cell cycle and causing dedifferentiation Cloning of Dolly Nucleus from mammary cell Grown in culture Early embryo Implanted in uterus of a third sheep Surrogate mother Embryonic development Lamb (“Dolly”) genetically identical to mammary cell donor

  6. Stem Cells • Embryonic Stem Cells- totipotent-can be anything • No genes are locked=can make any gene, protein, enzyme, • Adult Stem Cells-pluripotent-can be several things • Some genes locked, can be lots of different cells I can understand simple Mendelian genetic principles. I can work punnett squares.

  7. Embryonic stem cells Adult stem cells LE 21-9 Totipotent cells Pluripotent cells Cultured stem cells Different culture conditions Different types of differentiated cells Liver cells Nerve cells Blood cells

  8. Genetics…We are leaving the cell! • 1. When is DNA replicated in the cell cycle? • 2. Mitosis = _ divisions of the cell. • 3. Meiosis = _ divisions of the cell.

  9. MITOSIS MEIOSIS Chiasma (site of crossing over) Parent cell (before chromosome replication) MEIOSIS I Propase Prophase I Chromosome replication Chromosome replication Tetrad formed by synapsis of homologous chromosomes Duplicated chromosome (two sister chromatids) 2n = 6 . Chromosomes positioned at the metaphase plate Tetrads positioned at the metaphase plate Metaphase I Metaphase Anaphase Sister chromatids separate during anaphase Anaphase I Homologues separate during anaphase I; sister chromatids remain together Telophase Telophase I Haploid n = 3 Daughter cells of meiosis I 2n 2n MEIOSIS II Daughter cells of mitosis n n n n Daughter cells of meiosis II Sister chromatids separate during anaphase II

  10. Figure 9.15 The Human Karyotype DNA chromatin in Interphase in cell. Chromosomes have been stained in Metaphase to distinguish homologous chromsomes.

  11. Heredity= Passing traits from parent to offspring

  12. Chromosome Terminology • As a human you have 46 chromosomes in your somatic cells. • 23 from dad, 23 from mom. • You only have 23 chromosomes in your sex cells (egg/sperm).

  13. Homologous Chromosomes • Each of the 23 chromosomes inherited by your parents line up in pairs. • These pairs are known as homologous chromosomes. • These homologous chromosomes are identical in size, shape, and location of genes.

  14. Locus(Gene locations on chromosomes)

  15. Meiosis I • During Prophase I, a process called synapsis/ chiasmata occurs. Homologous chromosomes pair by adhering at their lengths. • Proteins aid in this adhesion by forming a scaffold called a synaptonemal complex. • The four bound chromatids form a tetrad. • How many chromatids are in human cells during Meiosis I? • 92

  16. Meiosis II Meiosis I and Meiosis II Meiosis I Homologues will meet and form a tetrad. Crossing over occurs: allele swapping. Telophase I- two new cells with one homologue per cell (still replicated chromatids) Prophase, Metaphase and Anaphase similar to Mitosis and Meiosis I. Telophase II results in four haploid daughter cells. One chromatid per cell

  17. Meiosis I • The chromatids that result are known as recombinant chromatids • Not all organisms directly enter Meiosis II. • If an organism does not, it does form a nuclear membrane at the end of Telophase I • Telophase I is followed by interkinesis, which is similar to mitotic interphase

  18. Meiosis II • Homologues are not identical like in Meiosis I because of crossing over. • The result is four haploid nuclei, with a single set of unreplicated chromosomes.

  19. So what causes genetic diversity • Synapsis, crossing over, and segregation of homologues • Aneuploidy- when there are either missing or excessive chromosomes. • Monosomy • Trisomy 10-30% human zygotes show trisomy • Aneuploidy, ~20% of miscarriages due to aneuploidy (extra or missing chromosomes) • Polyploidy complete extra sets of chromosomes, can occur naturally, can be result of genetic engineering • Aneuploidy Simulations- Utah Site

  20. Asexual reproduction (One parent)See the bud on the side… that is the “new” organism to be. • Benefits: Quick- good for takeover • Pitfalls: Because of no variety one parasite/pathogen and all die.

  21. Sexual Reproduction (Two parents) • Benefits: VARIATION • Pitfalls: Time, it takes 2, need opposite sexes, gametes are harder to make.

  22. Life Cycles Review: Haploid, Diploid, Alternation of Generations Key Haploid Diploid Haploid multicellular organism (gametophyte) Haploid multicellular organism Gametes n n Mitosis Mitosis Mitosis Mitosis n n n n n n n n n Spores n MEIOSIS FERTILIZATION Gametes Gametes n MEIOSIS FERTILIZATION MEIOSIS FERTILIZATION Zygote 2n 2n 2n 2n Zygote Diploid multicellular organism (sporophyte) 2n Diploid multicellular organism Mitosis Mitosis Zygote Most fungi and some protists Animals Plants and some algae

  23. Autosomes vs. Sex Chromosomes • Autosomes- chromosomes that codes for all traits except gender. • Homologous pairs #1-22 • Sex chromosomes- chromosomes that code for gender. • Homologous pair #23 • Karyotyping Activity I can understand simple Mendelian genetic principles. I can work punnett squares.

  24. Female (XX) Karyotype(Remember… “kary” means “nucleus”)

  25. Male (XY) Karyotype

  26. Figure 9.15 The Human Karyotype Where do homologous chromosomes come from? What phase are these homologous chromosomes next to one another?

  27. What are chromosome maps called?

  28. All three of these conditions cause a form of mental retardation.

  29. Mendel `1850s • Known as the Father of Genetics • Experimented with pea plants • He used “true-breeding” plants which were self-pollinating. • These would produce identical offspring. I can understand simple Mendelian genetic principles. I can work punnett squares.

  30. Mendel and His Peas • Mendel wanted to try cross-breeding pea plants. • Cut off the male parts (pollen), and dusted pollen from another plant to cause fertilization.aka cross-pollination. I can understand simple Mendelian genetic principles. I can work punnett squares.

  31. Mendel • Mendel studied seven different traits. • Trait- specific characteristic, like flower color. • P generation- parent generation. • F1 generation- offspring of the P generation. • Traits are controlled by genes. • Genes- segment of DNA • Allele- different forms of a particular gene • Ex. Hair color, eye color, plant flower color. I can understand simple Mendelian genetic principles. I can work punnett squares.

  32. Mendelian Principles • 1. Biological inheritance is determined by genes passed on from parents to offspring. • 2. Principle of Dominance- some alleles are dominant and some are not (recessive). • Mendel knew that dominant alleles would always be expressed, and • Recessive alleles would only be expressed when the dominant allele was absent, and there are two recessive copies. I can understand simple Mendelian genetic principles. I can work punnett squares.

  33. Dominant vs. Recessive • Dominant= capital letter • Recessive= lower case letter • If capital letter is present, then that trait is expressed. • Must have two lower case letters for trait to be expressed I can understand simple Mendelian genetic principles. I can work punnett squares.

  34. Practice • If (P) = purple, (p)= white what do the following flowers look like? • PP = ? • Pp = ? • pp = ? • Study for your quiz tomorrow I can understand simple Mendelian genetic principles. I can work punnett squares.

  35. Genotype vs. Phenotype • Genotype- gene combinations an individual possesses • Phenotype- what an individual looks like based on genotype I can understand simple Mendelian genetic principles. I can work punnett squares.

  36. Homozygous vs. Heterozygous • Heterozygous/ Hybrid: for a particular trait the individual has one dominant and one recessive allele. (Tt) • Homozygous/ Purebreed: for a particular trait the individual has both dominant or both recessive alleles. (TT, tt) I can understand simple Mendelian genetic principles. I can work punnett squares.

  37. Exploring Classroom Genetics I can understand simple Mendelian genetic principles. I can work punnett squares.

  38. Law of Segregation • Homologous chromosomes separate independent of one another… • Don’t get all of mom’s DNA or dad’s DNA I can understand simple Mendelian genetic principles. I can work punnett squares.

  39. Law of Independent Assortment • Just because you have one dominant gene, does not mean all of your genes are dominant. • They are inherited independent of one another I can understand simple Mendelian genetic principles. I can work punnett squares.

  40. Probability • The odds that a particular event is going to take place. • If you flip a coin, there is a ½ chance that it will land on heads. • Apply this concept to segregation of alleles. I can understand simple Mendelian genetic principles. I can work punnett squares.

  41. Punnett Squares: Monohybrid(4), Dihybrid (16), Trihybrid (64) • Used to predict possible offspring outcomes. • Cross one parent with another. • Tall (TT) x short (tt) • Genotypic Ratio: • Phenotypic Ratio: • # of Heterozygous Individuals: • # of Homozygous Individuals: I can understand simple Mendelian genetic principles. I can work punnett squares.

  42. Trihybrid Probability I can understand simple Mendelian genetic principles. I can work punnett squares.

  43. Pedigree • A chart that shows the phenotypes for an organism and all of its ancestors. • What is the difference between phenotype and genotype? I can understand simple Mendelian genetic principles. I can work punnett squares.

  44. Pedigree Organization • Squares=males • Circles=Females • Each generation is denoted by a roman numeral. • Each individual is numbered in the generation • Blood relations are linked by vertical lines. • Marriage relations are linked by horizontal lines. I can understand simple Mendelian genetic principles. I can work punnett squares.

  45. Make a Pedigree with a Phenotype for Hair Color • Use your Family starting with one set of your biological grandparents. • Shade in all circles/squares of brunette people, and leave blank all other hair colors. I can understand simple Mendelian genetic principles. I can work punnett squares.

  46. Mendelian Exception #1 • Incomplete Dominance- think of this as a blending of genes. • Neither gene is dominant. • Heterozygous genotype is a blend of the two alleles. • Red(RR) + White(WW) = Pink flower(RW) • 1:2:1 ratio of offspring phenotype I can understand simple Mendelian genetic principles. I can work punnett squares.

  47. Incomplete Dominance Practice • 1. A cross between a blue blahblah bird & a white blahblah bird produces offspring that are silver.  The color of blahblah birds is determined by just two alleles. a) What are the genotypes of the parent blahblah birds in the original cross? b) What is/are the genotype(s) of the silver offspring? c) What would be the phenotypic ratios of offspring produced by two silver blahblah birds? • 2.  The color of fruit for plant "X" is determined by two alleles.  When two plants with orange fruits are crossed the following phenotypic ratios are present in the offspring: 25% red fruit, 50% orange fruit, 25% yellow fruit.  What are the genotypes of the parent orange-fruited plants? I can understand simple Mendelian genetic principles. I can work punnett squares.

  48. Mendelian Exception #2 • Codominance- both alleles contribute to the phenotype. • Genes do not blend, but show up distinctly. • Blood type, calicos, roan cattle • Red bull (RR) x White Cow(WW) = Roan calf(RW) I can understand simple Mendelian genetic principles. I can work punnett squares.

  49. Codominance Practice • 1. Predict the phenotypic ratios of offspring when a homozygous white cow is crossed with a roan bull. • 2. What should the genotypes & phenotypes for parent cattle be if a farmer wanted only cattle with red fur? • 3. A cross between a black cat & a tan cat produces a tabby pattern (black & tan fur together). a) What pattern of inheritence does this illustrate? b) What percent of kittens would have tan fur if a tabby cat is crossed with a black cat? I can understand simple Mendelian genetic principles. I can work punnett squares.

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