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.html

(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/AB/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)

2. A nucleotide is made up of 1 sugar, 1

phosphate and 1 base

(Circle a nucleotide on your paper!)

(5)

A Nucleotide

SUGAR

PHOSPHATE

BASE

3. The nucleotides are connected together

by the phosphate and

the sugar

(Think: SSugars and PPhosphates=

“SSide PPoles” of the Ladder)

(5)

A

G

G

T

Purines Pair With PyrimidinesAdenine

Pairs With Thymine

Guanine

Pairs With Cytosine

(5)4.

•When the bases pair together, they form a Double Helix.

A

G

G

T

AA CC TT TT CC GG AA TT CC GG