1 / 13

Introduction to Genetics: Mendel's Pea Experiment

Learn about Gregor Mendel, his groundbreaking pea plant experiments, traits, genes vs. alleles, dominance, genotypes, and phenotypes in genetics.

esanabria
Télécharger la présentation

Introduction to Genetics: Mendel's Pea Experiment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Genetics Mendel and Traits

  2. Genetics is the study of heredity!

  3. Gregor Mendel • Grew up in small region of Austria that is now part of the Czech Republic • Many remember him as an Austrian monk

  4. Gregor Mendel • What did he do? • Bred pea plants to study inheritance • Why is his work important? • He discovered the basic principles of heredity • Father of Genetics!

  5. Mendel’s Pea Experiment:Why Peas? 1. Many varieties w/ examinable traits 2. Was able to have strict control over how the pea plants mated 3. Peas plants had many “either/ or” characteristics that could be examined

  6. What is a trait? What is a Trait? - Specific characteristic such as seed color or pod color in a pea plant.

  7. Seven Traits Examined by Mendel

  8. 7 Traits Examined by Mendel Plant Height Seed Shape Seed Color Seed Coat Color Pod Shape Pod Color Flower Position

  9. Genes vs. Alleles • Genes: Location of a specific trait on a chromosome • Alleles: alternate forms of a gene with a slight difference in base sequence (A vs. a)

  10. Dominant vs. Recessive • Dominant: • In a pair of alleles, when one allele is stronger than the other • This allele is expressed- the one that you can “see” • Recessive: • Weaker allele in a pair of alleles • The allele that is hidden • Example: The allele for tall pea plants (T) is dominant over short pea plants (t)

  11. Genotype vs. Phenotype • Genotype = genetic makeup of an individual (think “gene = genotype”) • Example: the genotype for a pure tall pea plant would be TT • Phenotype = the expression of the genotype or the physical characteristics that you can see (think “physical = phenotype”) • Example: If the genotype for height in a pea plant is tt, then you will see a short pea plant.

  12. Homozygous vs. Heterozygous • Homozygous • when both alleles in a pair are the same • think “homo = same” • also considered to be “pure” • Example: A pure tall pea plant is homozygous dominant • Genotype = TT • Heterozygous • when the alleles in a pair are different from each other (think “hetero = different”) • Example: Tall pea plant with genotype = Tt

  13. Trait Alleles Seed Shape Round (R ___) Wrinkled (rr) Seed Color Yellow (Y ___) Green (yy) Seed coat color Gray (W ___) White (ww) Pod Shape Smooth (S ___) Wrinkled (ss) Pod Color Green (G ___) Yellow (gg) Flower Position Axial (A ___) Terminal (aa) Plant Height Tall (T ___) Short (tt) Genetics Practice: Determining Genotypes and Phenotypes • What is the genotype of a heterozygous axial plant? ______________ • What is the genotype of a wrinkled, short pea plant? ______________ • What is the genotype of a purebred green pod plant? ______________ • What is the phenotype for a ss plant? __________________________ • What is the phenotype for a Aa plant? __________________________

More Related