Heredity

• Heredity


  The transmission of traits from one generation to the next
• Genetics


  The study of heredity and hereditary variation
• Traits


  • Passed from parent to offspring through genes
  • Segments of DNA that code for basic units of heredity
• Offspring acquire genes from parents

  In inheriting chromosomes
• Asexual reproduction


  Single individual, no fusion of gametes, clones are exact copies of parent, mutations are only source of variation
• Sexual reproduction


  Two parents, offspring are unique combination of genes from parents, genetically varied from parents and siblings, always unique and different
• Homologous chromosomes


  A pair of chromosomes of the same size, length, centromere position, carrying the same genetic information
• One homologous chromosome is inherited from mom and one is inherited from dad
• Karyotypes


  • A display of chromosome pairs ordered by size and length
  • Difficult to see sister chromatids in each pair
• Somatic (body) cells


  Diploid, or 2n: two complete sets of each chromosome
• Gametic (sex) cells


  Haploid, or n: one set of each chromosome
• Eukaryotes


  • Have DNA packaged in chromosomes
  • Two types of chromosomes: autosomes and sex chromosomes
• Life cycle


  1. Sequence of stages in the reproductive history of an organism from conception to its own reproduction

  2. Fertilization and meiosis alternate in sexual life cycles
• Fertilization is when a sperm cell (haploid) fuses with an egg (haploid) to form a zygote (diploid)