Science

• Cell Division


  The process by which a mother cell divides to give rise to two daughter cells
• Types of cell division

  • Mitosis
  • Meiosis
• Cell division


  1. Growth

  2. Repair

  3. Maintenance of organisms
• Mitosis


  • Results in genetically identical cells
• Meiosis


  • Produces sex cells with genetic variability
• Cell division


  1. Interphase

  2. Prophase

  3. Metaphase

  4. Anaphase

  5. Telophase
• Cell division is a highly regulated process that ensures the precise distribution of genetic material and organelles among the daughter cells
• Interphase


  The cell grows and copies its DNA
• Stages of interphase


  • G1: Cell growth
  • S: DNA synthesis
  • G2: More growth, preparation for mitosis
• Mitosis


  The cell divides its DNA and cytoplasm, forming two new cells
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase

  5. Cytokinesis
• Cell theory states that the cell is the smallest unit of life, all living organisms are made up of cells, and cells come from pre-existing cells
• Types of cells


  • Somatic cells
  • Gametes
• Somatic cells


  Body cells that undergo mitosis
• Gametes


  Sex cells that undergo meiosis
• Genetic material is DNA, which is organized into chromosomes
• Humans have 46 chromosomes (23 pairs)
• Diploid means a cell has two copies of each chromosome, and haploid means a cell has one copy of each chromosome
• Gregor Mendel is considered the father of modern genetics, he used pea plants to demonstrate how certain characteristics are passed through generations
• Hereditary traits demonstrated by Mendel

  • Seed shape
  • Seed color
  • Flower color
  • Pod shape
  • Pod color
  • Stem height
• Gene


  A specific part of DNA that controls a hereditary trait
• Humans have 46 chromosomes (23 pairs), with 2 copies of each gene (1 from each parent)
• Genotype


  The genetic makeup of an organism
• Phenotype


  The observable characteristics of an organism
• A Punnett square is a tool used to predict the genotype and phenotype of offspring
• Using a Punnett square

  1. Write the parents' genotypes on the outside

  2. Write the possible genotypes of the offspring on the inside

  3. Calculate the probability of each genotype occurring
• Punnett square examples


  • TT (dominant tall) x tt (recessive short)

  Tt (mixed hybrid) x Tt (mixed hybrid)
• Brown eyes are dominant (B) and will cover up blue eyes (b)