Lesson 1 Gen Bio

• Traits

  Heritable features of an organism
• When you resemble your siblings

  You share the same facial features and complexion
• Inherited traits


  • Widow's peak
  • Ability to roll your tongue
• Intelligence quotient (IQ) level

  A complex inherited trait
• Predicting genotypes and phenotypes

  Using the laws of inheritance
• Mendelian genetics

  The foundations and development of the study of heredity
• Mendelian laws of inheritance

  • Describe and apply
• Genetics

  The study of how traits are transmitted from parents to offspring
• Heredity

  The passing of traits from parents to offspring
• Branches of genetics

  • Molecular genetics
  • Cytogenetics
  • Transmission genetics
  • Population genetics
• Transmission genetics

  Also called classical genetics, the oldest subdiscipline of genetics that attempts to predict outcomes of reproduction
• Gregor Mendel was the Father of Modern Genetics
• Gregor Mendel

  • Farm tender
  • Beekeeper
  • Academician
  • Augustinian Monk
• Mendel performed his pea plant studies in the Augustinian monastery of St. Thomas
• Pisum sativum

  The legumes garden peas that Mendel chose for his hybridization experiments
• Reasons why peas are ideal for genetic studies

  • Exhibit vigorous growth
  • Can self-fertilize
  • Can cross-fertilize
• Previous notions of inheritance that Mendel faced

  • Pangenesis
  • Homunculus theory
  • Blending theory
• Pangenesis was the belief that seeds are produced in different organs and will later on gather to form the offspring
• Homunculus Theory -The invention of the microscope made people believe that sperm cells bear a homunculus or little man
• The blending theory of inheritance states that traits of parents blend every generation of offspring
• Chromosome

  A DNA molecule that serves as the repository of genetic information in cells
• Homologous chromosomes

  Chromosomes that occur in pairs
• Paternal chromosome

  Chromosome from the father or male parent
• Maternal chromosome

  Chromosome from the mother or female parent
• Gene

  The basic unit of heredity that controls the expression of a biological characteristic
• Characteristic

  A heritable feature of an organism
• Genes occur in pairs and control particular characteristics
• Alleles

  The alternative forms of a gene
• Genotype

  The pair of alleles that determines what forms of the trait will be expressed
• Homozygous genotype


  When the alleles are identical
• Heterozygous genotype


  When the alleles are different
• Phenotype

  The physical or chemical traits that are expressed in an individual
• The allele for round pea is the dominant allele, and the allele for wrinkled pea is the recessive allele
• Dominant trait

  The trait observed in hybrid plants
• Recessive trait

  The trait that does not appear in the hybrid plant
• Pea plant characters used by Mendel

  • Each exists in two variants
• Monohybrid cross

  Mating between two individuals involving one characteristic or one pair of contrasting traits
• In the monohybrid cross example, the height of pea is involved
• Allele

  The recessive allele for wrinkled pea
• Recessive trait

  The trait that did not appear in the hybrid plant