1. DNA – What is it & What does it do? Life Science 8 / Butler

2. The Structure of DNA DNA = __________________ Acid
Genetic material found in the __________ of a cell
Cells contain ________ of DNA in each cell
In humans:
DNA forms 23 homologous pair of _________
Chromosomes hold ____________: a section of DNA which codes for a specific _________
Humans have __________ of genes

3. DNA Structure shape = twisted ladder called a ______________________
Has 2 sides & rungs in between
Sub units = _________________
Have 3 parts:
____________________: sugar made
of 5 carbons linked together
2. ____________ group: phosphoric acid
3. 1 of the 4 types of ____________________

4. DNA Structure
Nitrogen bases ____________ up the same way every time to make the __________ of the ladder
(A)_______________+(T)_____________
(G)_____________ +(C)______________
Connected by a weak ______________ bond
________________ base pairs in human genome
Sides of ladder: 2 parts
Sugar (_______________)
Phosphate (_____________________)

5. History of DNA By the 1950’s many facts were known about DNA
Chargaff: discovered specific proportions of nitrogen bases (A-T) / (C-G)
#s of each pair were not the same

6. History of DNA
_______________________: scientist who had photographed DNA using Xrays to show the shape
Nucleotide bases were stacked one on top of the other
Her information became available to other scientists also researching DNA
1953: ____________& _____________
Proposed “double helix” model

7. Crick & Watson Model included: _____________ ladder structure
Composed of ___________________
____________________ bond together to form rungs
1962: won __________________ for model