DNA & the genome

• what is DNA?

  • a double-stranded polymer of 4 different nucleotides, wound to form a double helix
  • the genetic material of the cell found in its nucleus
  • DNA is contained in structures called chromosomes
• define genome

  the entire genetic material of an organism
• why is understanding the human genome important?

  • allows scientists to identify genes in the genome that are linked to different types of disease
  • understanding & treating inherited disorders
  • tracing human migration patterns from the past
• what is a chromosome?

  long, coiled molecule of DNA that contains genetic information in the form of genes
• how many chromosomes do human body cells have?

  46 chromosomes - 23 pairs
• how many chromosomes do human gametes have?

  23
• what is a gene?

  • small section of DNA on a chromosome
  • each gene codes for a particular sequence of amino acids, to make a specific protein