Mendelian GeneticsGregor Mendel
Austrian Monk1822-1884The Father of Modern GeneticsThe use of pea plantsMendel used pea plants for his studiesbut why?Many different observable traitsReproduced very quicklyHe could control which plants reproduced with each other
Traits that he was observingRound vs. wrinkled pea shapeTall vs. short Yellow vs. green color
Traits were easily seen from generation to generation
Allele- alternative versions of a trait or genesuch as tall vs. short or T vs. t
Homozygous vs. HeterozygousHomozygous- The alleles in a pair are identicalTT or tt
Heterozygous- The alleles in a pair are differentTtGenotype vs. PhenotypeGenotypePhenotypeThe genetic make-up of an organism
Bb, BB, or bbThe outward appearance of an organismExample: Brown Hair, tall, blue eyes, etc.
Mendels LawsRule of Unit Factors- each organism has 2 factors that control each of its traits
You have 2 alleles for each traitone from each parent!
Mendels Laws (continued)Rule of Dominance- Within any characteristic one allele appears more often than the other. This may give the appearance that that allele is stronger and the other is weak.
If you have a brown hair allele from mom and a blond hair allele from dad, you would only see brown because it is dominant to blond.Mendels Laws (continued)Law of segregation-Each organism can produce 2 different types of gametes because it has 2 different alleles. During fertilization, male a female gametes randomly pair to form 4 combinations of allelesMendels Laws (continued)Law of Independent Assortment- Genes for different traits are inherited independent of each other.
Punnett SquaresA chart used to solve genetic problems
Rules for Making a Punnett SquareFemale gametes (eggs) go down the sideMale gametes (sperm) go across the topCapital letters = dominantLower Case letters = recessive
Monohybrid CrossShowing only one trait.