Download
gregor mendel 1822 1884 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Gregor Mendel 1822-1884 PowerPoint Presentation
Download Presentation
Gregor Mendel 1822-1884

Gregor Mendel 1822-1884

188 Vues Download Presentation
Télécharger la présentation

Gregor Mendel 1822-1884

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Gregor Mendel1822-1884 Father of Genetics: Principles of biological and hereditary traits

  2. Austrian monk • Studied the inheritance of traits in pea plants • Developed the laws of inheritance • Mendel's work was not recognized until the turn of the 20th century Gregor Johann Mendel

  3. Between 1856 and 1863, Mendel cultivated and tested thousands of pea plants • He found that the plants' offspring retained traits of the parents Gregor J. Mendel

  4. Heredity- the passing of traits from parent to offspring. • Self-pollinate- A plant is often able to pollinate by itself because it contains both the male and female reproductive structures. This only requires 1 parent. • Dominanttrait- the trait observed when at least one dominant allele for a characteristic is inherited • Recessivetrait- a trait that is apparent only when two recessive alleles for the same characteristic are inherited • Genes- a segment of DNA that carries hereditary instructions and is passed from parent to offspring • Alleles- multiple forms of the same gene • Genotype- an organisms inherited combination of alleles • Phenotype- an organisms inherited appearance Vocab To Keep in mind

  5. Mendel stated that physical traits are inherited as “particles” • Mendel did not know that the “particles” were actually Chromosomes & DNA • Chromosome: a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. • Gene: a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring. Inheritance

  6. Can be grown in a small area • Produce lots of offspring • Produce pure plants when allowed to self-pollinate several generations • Can be artificially cross-pollinated Why grow peas?

  7. Mendel tested 7 traits: • Flower color • Flower position • Seed color • Seed shape • Pod shape • Pod color • Plant height Mendel’s tests

  8. Mendel crossed flowers that were true-breeding for each characteristic. • He crossed a purple (PP) flowered plant with a white (pp) flowered plant. (Parent Generation) The Peas

  9. The first generation (F1) of plants all had purple flowers. • Where did the white color go?? Purple Parent (Pp) PurpleParent (Pp) The Peas cont’d

  10. Mendel took two of his first generation (F1 x F1) purple flowered plants and crossed them together. • In the second generation (F2) he had 3 purple flowered plants, and 1 white flowered plant. Purple Parent (Pp) PurpleParent (Pp) The Peas cont’d

  11. Mendel noticed in the first generation, all of the white flowers seemed to disappear. • He called this a recessive trait. • The white color faded into the background at first. • It showed up in the next generation when he pollinated the flowers. Mendel & The Peas

  12. The color (purple) that seemed to mask over the recessive color was named the dominant trait. Mendel & The Peas

  13. Mendel was responsible for figuring out that each plant carried two sets of instructions for each characteristic (one from the “mom” and one from the “dad”). • Trait- a distinguishing quality or characteristic, typically one belonging to a person Traits

  14. 1. If you crossed a true-breeding black rabbit with a true-breeding white rabbit, all of the offspring would be black. Which trait is dominant in rabbits: black fur or white fur? • Which trait is recessive? Test your knowledge

  15. White Rabbit (bb) Black Rabbit (BB) • The trait for black fur is dominant over the trait for white fur. The white fur trait is recessive. And the answer is….

  16. Heredity- the passing of traits from parent to offspring. • Self-pollinate- A plant is often able to pollinate by itself because it contains both the male and female reproductive structures. This only requires 1 parent. • Dominanttrait- the trait observed when at least one dominant allele for a characteristic is inherited • Recessivetrait- a trait that is apparent only when two recessive alleles for the same characteristic are inherited • Genes- a segment of DNA that carries hereditary instructions and is passed from parent to offspring • Alleles- multiple forms of the same gene • Genotype- an organisms inherited combination of alleles • Phenotype- an organisms inherited appearance Review

  17. Any last questions???