Bio ~ 12.1 and 12.2

• What plant did Gregor Mendel work with?

  Pea plants
• Gregor Mendel 


  A monk who is considered the “father of genetics”, controlled fertilization of pea plants and studied their traits (helped us understand modern genetics)
• Genetics 


  The study of heredity or how traits are passed from one generation to the next
• Female Plant Part 


  Pistil: Produces eggs (female reproductive cells)
• Male Plant Part

  Stamen: Makes pollen (has sperm, a males reproductive cells)
• Fertilization 


  A process during sexual reproduction where male and female cells join together to produce a new cell (a zygote)
• Self Pollination 


  When sperm cells fertilize eggs cells from within the same flower
• Self Pollination Plant 


  Inherits all of the characteristics from the single plant that bore it, makes identical offspring
• Trait 


  A specific characteristic of an individual (hair skin eye color, height, facial structure, etc.), can different from person to person
• Cross Pollination

  Where a plant offspring has 2 parents (meaning parts from 2 different flowers came together)
• Heredity 


  Delivery of characteristics from parent to offspring
• P


  Parent/parental generation
• F1 


  First filial generation (offspring of parents)
• F2 


  Offspring of F1 generation
• Some Things Mendel Studied

  Color of peas, pea shape, the actual pea pod, the pea seed coating, size of pea plant, placement of flowers on plant, etc.
• Mendel’s 1st Conclusion

  An individuals characteristics are determined by factors that are passed from 1 parental generation to the next
• Genes 


  Factors that are passed from parent to offspring; a segment of DNA that encodes information for a specific trait
• Alleles 


  Different forms of a gene (Example: gene=hair color, alleles= blonde or brown hair); term reffering to the alternative variations in a trait
• Mendel’s 2 Conclusion

  Principle of Dominance
• Principle of Dominance 


  States that some alleles are dominant and others are recessive;
• Dominant Allele 


  The stronger trait (more “popular”), need the genotypes of Tt or TT to have a dominant trait; only 1 copy of the allele needs to be present to see this trait
• Recessive Alleles 


  Weaker trait (less common to receive it), only when the genotype is tt that this trait will be shown; 2 copies of the trait must be present to see this trait
• Punnett Square 


  Tool to keep track of the gametes and possible offspring combinations
• Reginald Punnett


  Invented the Punnett square
• Why do we resemble our parents?

  We inherit their individual characteristics
• 3 Reasons why GM used pea plants

  They were easy to grow, they have many different traits to study, and their traits are easier to track from generation to generation
• Self-Fertilization vs Cross-Fertilization 


  SF: an offspring that is fertilized by 1 flower (the male parts fertilized the eggs cells from the same flower = 1 parent)

  CF: an offspring that is fertilized by 2 different flowers (the male parts come from 1 plant, and they are used to fertilize the eggs cells of another flower = 2 parents)
• Pure Bred Plants

  Contains 2 copies of the SAME gene for each trait (plants that only have 1 parent)
• What did Mendel mean when he said that each trait in a pea plant has alternative forms?


  He was saying that for every trait like the pea shape, there are different types/forms of that trait (like a round pea seed and a wrinkled pea seed)
• Phenotype 


  Visible and distinctive traits that are inherited in predictable ways (the traits that someone ends up with); physical appearance of an organism
• Genotype 


  An organisms genetic makeup (the letters); an organisms genetic makeup
• What would happen if the parents passed both copies of their gene pairs to their offspring (both of their letters)


  The offspring would end up with 4 genes which is double what they are supposed to have
• Gamete 


  A sex cell (sperm and egg cells)
• Mendel’s Law of Segregation

  Each trait that is defined by a pair of genes. Each parent can make 2 types of gametes, which means each allele is randomly separated into each gamete; when an organism produces gametes, the 2 alleles seperate from 1 another so that each gamete carries only 1 allele
• Heterozygous 


  Organism that has 2 different copies of an allele (cross–bred/hybrid organism, Yy); pairs of alleles present in a hybrid organism
• Homozygous 


  Organism that has 2 identical copies of an allele (Pure bred organism, YY or yy); pairs of alleles present in a pure bred organism
• What did Mendel contribute to in Genetics?


  The Law of Inheritance, Segregation, Dominance and Recessiveness, Genetic Variation
• How did M’s experiment give evidence for the principle of IA?


  It showed that there were some seeds who did not have the same genotype as their parents, showing that during meiosis the alleles separated randomly into the cells
• How can we use probability to predict traits?


  Can use it to figure out which genotypes are possible based off of what alleles the organism has, higher percentage of a genotype leads to a higher chance of that trait and vice versa
• Where does an organism gets it’s unique characteristics?

  Inherit them from their parents