History of Genetics/
INTRO TO DNA
(1) Gregor Mendel
“The Father of Genetics”
• A Monk: Studied pea plants in
in a garden
» Discovered dominant
and recessive traits
http://www.nlm.nih.gov/visibleproofs/galleries/technologies/dna.ht
(2) Rosalind Franklin
• Created images of
the DNA molecule
that showed its
spiral shape.
http://profiles.nlm.nih.gov/KR/B/B/J/N/
http://www.accessexcellence.org/RC/A
B/WYW/wkbooks/SFTS/SFTSg/1.jpg
(3) James Watson &
Francis Crick
• These two
scientists
discovered the
complete structure
of DNA
• “The Double Helix”
http://www.achievement.org/autodoc/photocredit/achievers/wat0-001
The Structure of DNA
(4) Shape
• DNA has a
double helix
shape
•
• If you took a
ladder and
twisted it, it
would look like
DNA
Composition
(5)
1. DNA is made up
of phosphates,
sugars,
and bases (purines
and pyrimidines)
(5)
2. A nucleotide is made
up of 1 sugar, 1
phosphate and 1 base
(Circle a nucleotide on
your paper!)
A Nucleotide
PHOSPHATE
BASE
SUGAR
(5)
3. The nucleotides are
connected together
by the phosphate and
the sugar
(Think: Sugars and Phosphates
=
“Side Poles” of the Ladder)
A
T
G
G
(5)
4.
•When the bases pair together,
they form a Double Helix.
Purines Pair With
Pyrimidines
Adenine Pairs With
Thymine
Guanine Pairs With
Cytosine
A
T
G
G
A
C
T
T
C
G
A
T
C
G