The

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• The
• Structure
• of
• DNA

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Cut, color and glue the illustration of the DNA
double helix onto the output page of your
notebook. Do the following

• Label the components that make up the DNA.
• 2. Draw a box surrounding one nucleotide of the
  double helix and label this.

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All life on earth uses a chemical called DNA to
carry its genetic code or blueprint. In this
lesson we be examining the structure of this
unique molecule.
By the way, can you make out what this is?
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Why do we study DNA? Why is it important?

• We study DNA for many reasons, e.g.,
• its central importance to all life on Earth/
  identifies organisms,
• HowStuffWorks Videos "Solved DNA Analysis"
• medical benefits such as cures for diseases or
  risks for genetic diseases
• http//www.redorbit.com/news/video/science/5/dna_t
  esting_for_everyone/25395/index.html

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Essential Questions

• How can we tell if organisms are related to each
  other and how organisms change over time?

• How is DNA similar to the Morse Code or any other
  secret codes?

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DNA??????

• DDeoxyribo
• NNucleic
• AAcid
• Deoxyribonucleic Acid

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What is DNA?

• DNA is often called the blueprint of life.
• In simple terms, DNA contains the instructions
  for making proteins within the cell.

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Chromosomes and DNA?

• Our genes are on our chromosomes.
• Chromosomes are made up of a chemical called DNA.

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The Shape of DNA?

• DNA is a very long polymer.
• The basic shape is like a twisted ladder or
  zipper.
• This is called a double helix.

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The Double Helix Molecule

• The DNA double helix has two strands twisted
  together.

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DNA Double Helix

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What makes up the strand (rails) of DNA?
phosphate

• The backbone of the molecule is alternating
  phosphates and deoxyribose sugar

deoxyribose
bases
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What are the four nitrogenous bases that make up
the steps of the ladder?
DNA has four different bases

• Cytosine C
• Thymine T
• Adenine A
• Guanine G
• THESE MAKE UP THE STEPS OF THE LADDER!!!

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nucleotide

• DNA is made up of repeating units called
  nucleotides

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What makes up the DNA Nucleotides?

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Cut and glue the nucleotide illustration onto the
output page and label its three parts (pay close
attention to the attachments)
A.
C.

• A. Phosphate group
• B. Deoxyribose sugar
• C. Nitrogen base

B.
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Chargaffs Rule

• DNA has specific pairing between the nitrogen
  bases
• Adenine must pair with Thymine
• Guanine must pair with Cytosine
• Their amounts in a given DNA molecule will be
  about the same.

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BASE-PAIRINGS

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Two Stranded DNA

• Remember, DNA has two strands that fit together
  something like a zipper.
• DNA was made of 2 long stands of nucleotides
  arranged in a specific way called the
  Complementary Rule

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Genetic Diversity

• Different arrangements of NUCLEOTIDES in a
  nucleic acid (DNA) provides the key to DIVERSITY
  among living organisms.

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The Code of Life

• The code of the chromosome is the SPECIFIC
  ORDER that bases occur.
• A T C G T A T G C G G

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QUIZ
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• 1. Which of the following bases pairs with
  adenine in DNA?
• Thymine
• Guanine
• Adenine
• Cytosine

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What is the DNA base pair rule?
2. If the template of a strand of DNA is 5'
AGATGCATC 3 ,the complementary strand will be
F 3' TCTACGTAG 5' G 5' CTACGTAGA 3' H 3'
AGATGCATC 5' J 5' AGACGTCTA 3'
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3. In DNA, which of the following determines the
traits of an organism?

• F Amount of adenine
• G Number of sugars
• H Sequence of nitrogen bases
• J Strength of hydrogen bonds

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4. A biologist collects DNA samples from 2
sisters. The younger sister has blond hair. The
older sister has red hair. The sisters have
different traits because their DNA contains
different

• A. orders of nucleotides
• B. types of sugar molecules
• C. sized phosphate groups
• D. types of nitrogenous bases

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5. In all plants and animal cells, the nucleus
contains long molecules of DNA. Which of the
following best describes the function of DNA

• DNA provides the shape and structure of the
  nucleus.
• DNA packages materials for transport through the
  nucleus.
• DNA carries materials into and out of the
  nucleus.
• J. DNA contains the blueprint for producing
  the whole organism.

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Assignment

• Create a paper model of the double helix paying
  close attention to the components that make up
  the nucleotides!