Post on 01-Jan-2016
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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
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
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
The Shape of DNA
• A DNA molecule looks like a spiral staircase and is composed of two parallel strands of linked subunits called nucleotides
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
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)