Introduction to genetic material

• • Nucleus = contains genetic material in the form of chromosomes which controls cellular activities.
• • Chromosomes = long strands of tightly packed DNA.
• • Gene = A section of DNA that codes for characteristics and proteins.
• DNA Structure

  • Has the shape of a helix like a twisted ladder
  • A double helix is two polynucleotide pairs twisted together.
  • What are the pairs for the DNA strands? A+T and C+G
• Describe the shape of a helix

  • Twisted ladder
• What is a double helix?

  two polynucleotide pairs twisted together
• what do the base letters stand for?

  There are 4 nitrogenous bases found in DNA are ...

  • C = Cytosine
  • A = Adenine
  • T = Thymine
  • G = Guanine
• nucleotides = unit found in DNA , made up of nitrogenous base , deoxyribose sugar and a phosphate group.
• What is this photo showing?

  Nucleotides

  
• polymer = substance made up of many monomer bonded together. long chain of repeating units
• Label what the photo is showing

  DNA double helix

  • Red - Nucleotides polymer chains
  • Blue - nitrogenous base pars

  
• Each cell in your body has 23 pairs of chromosomes - they are pairs because one copy is from your mother ( maternal) and one copy is from your father ( paternal).
• • Biological male have xy chromosomes at pair 23
  • Biological female have xx chromosomes at pair 23