chromosomes and sex cells

• somatic cells - greek word soma meaning body

  • contains complete chromosome
  • forms the body tissues and organs
  • cannot pass DNA
• germ cells - specialized cells that are involved in sexual reproduction

  • responsible for passing genetic information
• number of chromosomes in different species

  • great apes - 48 or 24 pairs
  • domestic dogs - 78 or 39 pairs
  • domestic cat - 38 or 19 pairs
  • house mouse - 40 or 20 pairs
  • fruit fly - 8 or 4 pairs
  • ophioglossum - 1260
• homologous pair - known as "homologs"

  • chromosome pairs that are similar in size, shape, and gene content
• karyotyping - a laboratory technique
• karyogram - visual representation of an individual's karyotype
• autosomes - chromosome pairs 1-22
• sex chromosome - special twenty-third pair
• two X chromosome is female
• X & Y chromosomes is male
• X chromosome is larger containing more genes
• Y chromosome is the smallest chromosome containing few genes
• gametes - "sex cells"