Genetics - Mandel's Pea Plant

• Traits


  Characteristics inherited from parents
• Scientists can calculate probabilities of having a specific trait or getting a genetic disease according to information from parents and family history
• Gregor Mendel


  Austrian monk and biologist who discovered the principles that rule heredity by breeding pea plants
• Mendel's experiment with pea plants

  1. Crossed purebred yellow-seeded plant with purebred green-seeded plant

  2. Got only yellow seeds in first generation

  3. Let the yellow-seeded hybrid plants self-fertilize

  4. Got both yellow and green seeds in second generation
• Dominant trait


  Trait that is expressed in all the new seeds
• Recessive trait


  Trait that is hidden by the dominant trait
• Alleles


  Factors that determine a trait, one from the mother and one from the father
• Homozygous


  When both alleles are identical
• Heterozygous


  When the two alleles are different
• Genotype


  Combination of alleles
• Phenotype


  Result of the genotype, being yellow or green
• Punnett square


  Diagram used to visualize how alleles are distributed amongst descendants
• Pea plant characteristics


  • Yellow or green
  • Round or wrinkled
• There are many other ways in which some characteristics are inherited besides the ones described for peas
• Mendel's work with peas laid the foundation for our modern understanding of genetics and heredity