1. The Structure of DNA

2. DNA: The Genetic Material Mendel (1800’s) showed that traits are passed from parents to offspring

3. DNA: The Genetic Material The instructions for inherited traits are called genes – 1950’s – scientists determined that genes were made of DNA DNA: primary material that causes recognizable, inheritable characteristics in related groups of organisms

4. Discovering DNA’s Structure Rosalind Franklin used x-ray diffraction to determine the structure of DNA – Images suggested DNA resembled a tightly coiled helix composed of two chains of nucleotides

5. Discovering DNA’s Structure Watson and Crick constructed a 3D model of DNA – Used information from experiments conducted by other scientists – Determined the structure of DNA was a double helix made of two strands of nucleotides – Won Nobel Prize in 1962

6. The Shape of DNA A DNA molecule looks like a spiral staircase and is composed of two parallel strands of linked subunits called nucleotides

7. The Shape of DNA A nucleotide has 3 parts: phosphate group, sugar (deoxyribose), and a base The phosphate and sugar link together to form the back bone The bases pair together to connect the two strands

8. DNA Assignments DNA – The Double Helix practice sheet Build a 3D DNA Model Build a DNA Molecule Online Activity: http://learn.genetics.utah.edu/content/begin/dna/builddna/ (see my webpage for link)