Genetics

• Genetics is the study of inherited traits and their variation
• Heredity is the transmission of traits and biological information between generations
• Genealogy considers relationships but not traits
• Inherited traits range from obvious physical characteristics to aspects of health, talents, quirks, and personality traits
• Traits can be a combination of genetic and environmental influences
• Genes are the units of heredity
• Genome refers to the complete set of genetic instructions characteristic of an organism
• Alleles are different forms of genes
• Pure breeding occurs when mated with their own kind, and all the offspring resemble their parents
• Character refers to observable physical features, while trait forms a character (e.g., flower color)
• Gregor Mendel was the first thinker to probe the underlying rules of logic for predicting inheritance of specific traits
• Mendel described units of inheritance that pass traits from generation to generation
• Mendel's experiments with garden peas laid down the basic principles of inheritance
• Pea plants were chosen for Mendel's experiments due to being perennial, self-pollinating, and having easily observable contrasting traits
• The parental generation is the first generation (P1), followed by the first filial generation (F1), and the second filial generation (F2)
• Genotype is the gene pair an individual carries for a particular trait, symbolized with a pair of letters
• Phenotype is the observable trait of an individual based on its genotype
• Punnett square is a tool to calculate the mathematical probability of inheriting a specific trait
• A genetic test cross can reveal the genotype of an individual with a dominant phenotype
• A dihybrid cross involves a cross between two different lines that differ in two observed traits
• Methods in Plant Breeding:

  • Self-Pollination: pollen transfer between the anther and stigma of the same flower
  • Cross-Pollination: pollen transfer between the anther and stigma of different flowers of the same plant or different plants of the same species
• Breeding Self-Pollinating Species:

  • Mass Selection: choosing ideal plants from a large number of populations to serve as breeding parents
  • Pure-Line Selection: selecting superior looking plants from a population and evaluating their progenies over several years
  • Hybridization: crossing carefully selected parent plants
• Development of Hybrid Varieties in Cross-Pollinated Plant Species:

  1. Selecting superior parent plants of different varieties

  2. Self-pollinating the parent plants for several generations to produce inbred lines

  3. Crossing selected inbred lines
• Animal Breeding:

  • Follows similar procedures as plant breeding such as mass selection, inbreeding, and outbreeding
  • Animals are usually bred for utility, sport, pleasure, and research
• Genetic Engineering Vocabulary:

  • Gene Splicing: cutting the DNA of a gene to add new base pairs
  • Genetic Engineering: direct manipulation of DNA for practical purposes
  • Biotechnology: use of organisms or their components to make useful products
  • Transgenic Organism: contains a gene from another organism, typically a different species
  • Genetically Modified Organisms (GMOs): organisms that have acquired one or more genes by artificial means
• Role of Enzymes in Genetic Engineering:

  • Restriction Enzymes: scan DNA for specific sequences and cut the strand at those points
  • Ligase: joins isolated DNA pieces to the DNA of a recipient organism (plasmid)
• Recombinant Technology:

  • Allows genes from different species to be combined into a single DNA molecule
• Steps to Remove and Insert Genes in Genetic Engineering:

  1. A restriction enzyme cuts the DNA into fragments

  2. A DNA fragment from another source is added

  3. Fragments stick together by base pairs

  4. DNA Ligase joins the fragments into strands
• Application of Recombinant DNA:

  • Hepatitis B Vaccine
  • Pest-Resistant Plants like Bt corn
  • Herbicides-Resistant Plants
  • Increase Nutritional Value like Golden Rice
• Pattern of Development in writing

  Refers to the particular strategy writers use to develop ideas. It is the logical arrangement of thoughts
• Narration


  • A method of development where storytelling is used to develop ideas effectively as people enjoy stories
• Narration


  • I took up the river road as hard as I could put. By and by I begin to hear guns a good ways off...
• Concrete and Specific Detail


  • Specific details are more detailed, while general details are broad
• Concrete and Specific Detail

  • Blue hamster/pet
  • Banana squash/vegetable
  • Red and white umbrella with a broken spoke/rain gear
• Concrete/Abstract


  • Concrete details provide specific information, while abstract details are more general
• Concrete/Abstract


  • He kissed her and smiled into her eyes. / He loved her.
  • Her hands were shaking and she was afraid her knees would not support her. / She was scared.
• Description


  • Provides details on the idea by using a sensory or spatial pattern. Ideas are arranged based on one or all of the five senses
• Subjective Description


  • Descriptive paragraphs are used most often in fiction to create a subjective impression
• Subjective Description


  • “It was a dark and stormy night” “The mountains loomed above them”
• Objective Description


  • Used in reportorial and scientific writing to present an objective picture of an object or scene