LESSON 3

• Chromosomes


  Rod shaped structures made of DNA and proteins found in the nucleus of cells
• Chromatids


  • Two identical halves
  • When cell divides, each of the two new cells will receive one chromatid
• Centromere


  • When two chromatids are attached, between cell division, DNA is not so tightly coiled
• Telomeres


  • Structures made from DNA sequences and proteins found at the ends of chromosomes
• P arm


  • The UPPER arms of chromosome which is usually SHORTER
• Q arm


  • The lower arms of chromosome which is usually longer
• Animal chromosomes

  • Autosomes
  • Sex chromosomes
• Every cell of an organism produced by sexual reproduction has two copies of each autosome, one from each parent
• Sex chromosomes


  Determine the sex of an organism
• Homologous chromosomes


  Same size and shape and carry genes for the same traits
• Haploid


  • Cell that have a 1 set of chromosomes (23 total in human)
  • Non-Homologous chromosome
  • Meiosis
• Diploid


  • Cells that have 2 sets of chromosomes (46 total in human)
  • Pairs of homologous chromosome
  • Mitosis
• Cell cycle

  1. Interphase

  2. M phase
• Cell


  The basic unit of life
• Interphase


  • Increased cell size and DNA replication in preparation for cell division
• G1 phase


  • The stage from the formation of a new cell until it begins to replicate its DNA
  • Proteins are produced
• 1. phase


  • DNA replication occurs, where the cell makes a copy of its DNA
• G2


  • The cell continues to grow and prepares for cell division