Chromosomes cyto

• Chromosomes


  • Darkly-staining definite bodies within the nucleus of a eukaryotic cell
  • Consist of DNA, RNA and protein
• Chromosomes


  • Structures within the living cells that contain the genetic material
  • In eukaryotic cells, this complex between DNA and protein is chromatin
• Chromosomes Size


  • Plants usually have longer chromosomes than animals
  • Plant Chromosomes are generally 0.8 -7um in length where as animal chromosomes are 0.5-4um in length
  • Chromosomes size varies from species to species
• Chromosomes Structure


  • Centromere
  • Chromatid
  • Secondary Constriction and satellite
  • Telomere
  • Chromomere
  • Chromonema
  • Matrix
• Karyotype


  1. Add phytohemagglutinin and culture medium

  2. Culture at 37°C for 3 days

  3. Add colchicine and hypotonic saline

  4. Cells fixed

  5. Digest with trypsin and stain with Giemsa

  6. Spread cells onto slide by dropping
• Inversions


  A portion of the chromosomes has broken off, turned upside down and reattached, therefore the genetic materials is inverted and sequence is distributed
• Insertion


  A portion of one chromosomes has been deleted from its normal place and inserted into another chromosomes
• Types of Aneuploidy

  • Monosomy - the loss of a single chromosome
  • Nullisomy - the loss of both homologous chromosomes
  • Trisomy - the gain of an extra copy of a chromosomes
  • Tetrasomic - the gain of an extra pair of homologous chromosomes
• Jacob's Syndrome occurs in 1 in 1,800 births