1. Intro. to DNA & Genetics

2. Why/how do children resemble their parents?
Heredity: the passing of characteristics from parents to offspring
The study of heredity is what led to the study of genetics and DNA.
Genetics: the science of heredity and of the mechanisms by which traits are passed from parents to offspring

3. DNA
James Watson and Francis Crick are the scientists that pieced together a model and discovered the structure of DNA.
Discovering the structure of DNA clarified how the DNA could serve as the genetic material.
DNA=deoxyribonucleic acid

4. DNA Structure
Double helix-two strands twisted like a winding staircase
Each strand is made up of nucleotides.
Every nucleotide is made up of three parts:
phosphate group
5-carbon sugar
nitrogenous base

5. DNA Structure
The sugar (deoxyribose) and the phosphate group stay the same, but the nitrogenous base may be any of 4 different kinds
Adenine
Guanine
Cytosine
Thymine

6. DNA Structure Purine-two rings of carbon and nitrogen atoms
Adenine and guanine are purines.
Pyrimidine-a single ring of carbon and nitrogen atoms
Cytosine and thymine are pyrimidines.

7. DNA Structure
Base pairing rules-a purine on one strand always pairs with a pyrimidine on the other strand
adenine – thymine (complementary base pairs)
cytosine – guanine (complementary base pairs)
Hydrogen bonds link the two nitrogenous bases together to connect the two strands.

9. Complementary Strand Practice:
AAACCGTTGAGA
GAGATCATAGCC
CACGTTATACGA
ATTTGCCAGACT
TGCCTAAGGCAT