1. Unit 2 LE4 The Language of Heredity
The history of DNA

2. 1. Who was the first to study inheritance of traits?
Gregor Mendel 1866

3. Large amount found in cells
Numerous functions within cell
Made up of 20 amino acids with almost an infinite number of combinations
Allow for the diversity of traits seen
2. Why did some scientists believe protein was the molecule that stored information?

4. What does this picture represent? Nucleotide Label the 3 parts3.
Nitrogenous base
What does this picture represent?
Nucleotide
Label the 3 parts
Phosphate
Sugar:
Deoxyribose

5. 4. What did Oswald Avery show in 1943
That DNA directs the expression of traits within an organism and transfers from one generation to the next

6. That DNA is the molecule that transfers information for traits
5. What question did Hershey and Chase answer in their experiment in 1952?
That DNA is the molecule that transfers information for traits
Was it DNA or proteins that express traits?

7. 6. What was the bacteriophage experiment that proved DNA is genetic material?

8. Chargaff’s Rule
What does the table tell you about the DNA in all organisms?
What about the proportions in humans?
All organisms contain the 4 bases: adenine, thymine, guanine and cytosine
Equal proportions of A&T and C&G
= 60%
= 40%
100%

9. What are the facts about the structure of DNA?
Made up of 6 parts
Phosphorus
Sugar
4 nitrogenous bases
Double helix
2 strands
Opposite directions
Form complimentary pairs
Hydrogen bonds between bases
What are the facts about the structure of DNA?

10. Timeline: Mendel, Johannsen, Bateson, Griffith, Avery, Hershey & Chase, Chargaff, Franklin, Watson & Crick
Mendel
1866