le 1 genetics

• Mendelian and Non-Mendelian Genetics
• Sex Chromosome & Sex Determination
• Non-Mendelian Ratios


  Does not follow the rules that was observed in Mendelian Genetics
• Gregor Johann Mendel


  • Born in 1822
  • Took the name Gregor when admitted to the Augustinian Monastery of St. Thomas in Brno
  • Studied physics and botany at the University of Vienna
  • Performed his first set of hybridization experiments in 1856
  • Died of kidney disorder in 1884
  • Father of Genetics
  • Not the first to study about inheritance but his success was attributed to his elegant experiment design and analysis
• Mendel's Postulates


  • Unit factors in pairs
  • Dominance/recessiveness
  • Segregation
  • Independent assortment
• Unit factors


  Genetic characters are controlled by unit factors existing in pairs in individual organisms
• Dominance/recessiveness


  When two unlike unit factors responsible for a single character are present in a single individual, one unit factor is dominant to the other, which is said to be recessive
• Segregation


  During the formation of gametes, the paired unit factors separate, or segregate, randomly so that each gamete receives one or the other with equal likelihood
• Independent assortment


  During gamete formation, segregating pairs of unit factors assort independently of each other
• Gregor Mendel was successful because he looked for the characters with opposing traits using the peas
• The trait of a person that is capable of looking at that type of observation is very important
• Examples of contrasting traits


  • Seed color: yellow or green
  • Pod shape: full or constricted
• When you look at the phenotype, it is 3:1 or rounded off to 3:1
• The 3:1 ratio is considered as or observed in a single phenotype
• Phenotype


  Physical expression of a trait
• Genes


  Units of inheritance
• Alleles


  Alternative forms of a single gene
• Genotype


  Designates the genetic makeup of an individual for the trait or traits it describes (either haploid or diploid)
• Homozygous


  When both alleles are the same
• Heterozygous


  When the alleles are different
• P1 generation


  Generation of the parent
• F1 generation


  Generation of the offspring
• F2 generation


  Generation of the second offspring
• Hugo de Vries


  • Concept of genes
  • Term "mutation"
  • Mutation theory of evolution
• Carl Correns


  • Independent discovery of "hereditary"
  • Worked unknowingly in the concept of genetics
  • Cytoplasmic inheritance
• Erich von Tschermak-Seysenegg


  • Developed disease-resistant crops
• Golden Rice is very specific about Vitamin A
• Golden Rice does not cause harm as of now since it has been produced and the gene is stable
• Breeding is the same method as gene modification, just sped things up
• Beta-carotene


  The one that exists normally, but it shall be catalyzed by the body to form vitamin A
• Golden Rice is more applicable to the medical side rather than solving food security
• Eating rice alone is unhealthy
• Gene modification is done to speed things up
• The issue with gene modification is that when researchers need money, companies provide the fund and gain the rights to the study
• Monohybrid cross


  Reveals how one trait is transmitted from generation to generation
• A cross between a pea plant that is homozygous for yellow seed (YY) and a pea plant that is homozygous for green seeds (yy) will produce only yellow heterozygous offspring (Yy)
• Punnett square


  A chart used to track the contributions of each parent to the genotype and phenotype of the offspring
• If you're given with only tall phenotype in F2 generation, you can use a Testcross to distinguish the genotype
• Dihybrid cross


  Examines two characters simultaneously
• In the dihybrid cross, the ratio for the phenotype is 9:3:3:1