1. Modern Genetics

2. DNA Genetic material in the chromosome. DNA=Deoxyribonucleic acid
DNA is made up of small subunits called nucleotides.
DNA is found in the nucleus.

3. The Nucleotide Each nucleotide consists of 3 parts:
5 carbon sugar called deoxyribose
Phosphate group
Nitrogenous base

4. Four bases: The Nitrogen Bases Adenine (A) Thymine (T) Guanine (G)
Cytosine (C)

5. Types of Nitrogen Bases
Purines:
Adenine (A)
Guanine (G)
Pyrimidines:
Thymine (T)
Cytosine (C)

6. Base Pairing Rule A pairs with T C pairs with G
Held together by Hydrogen Bonds

7. Watson and Crick Model of DNA
Shape of DNA
Double helix, twisted ladder
Sides of the ladder consists of alternating sugar phosphate molecules
Rungs of the ladder consist of nitrogenous base pairs

8. The Story of the DNA’s Discovery

9. DNA Replication
Double stranded DNA molecule unzips along the hydrogen bonds located between nitrogen bases.
Free nucleotides that are present in the nucleus attach themselves to the exposed bases.
The new double stranded DNA molecules that are identical to the original molecule are produced.

11. Helicase & DNA Polymerase