1. DNA: Structure and History
Honors Biology

2. DNA is a chemical!!
Strawberries
Human

3. Functions of DNA: -stores all your body’s information
Passes information from parents to offspring
(heredity or hereditable characteristics)

4. DNA is made of smaller parts called: Nucleotides
Nucleotides contain 3 parts:
Phosphate
Sugar
Nitrogen Base

5. Things to Know: There are four types of nitrogen bases in DNA:
A- adenine
T- thymine
C- cytosine
G- guanine

6. Things to Know: There are two sides to DNA Appears like a ladder:
Sides are phosphate and sugar
Steps are the base pairs
Base Pair Rule:
A-T are complimentary
C-G are complimentary

7. Can you see the ladder?

8. The DNA ladder is twisted
This twist is called a “helix”

9. DNA is called the double helix because it is a two sided, twisted ladder.

10. History…
1952 – Rosalind Franklin used X-ray diffraction to show helical structure of DNA

11. The biggest event in DNA history…
1953 – James Watson and Francis Crick discover the 3-D structure of DNA

12. The Basics 1. All living things have DNA
2. The amount and sequence (or order) of ATGC makes us different from each other and other living things

13. 3. Small parts of the DNA that contain a specific instruction is known as a gene

14. 4. Genes in the DNA are the body’s directions for making proteins
Proteins make us:
look the way we do
function the way we do
develop and grow the way we do
behave the way we do
think the way we do

15. You and the person next to you have 99.9% the same DNA!!
How is that possible?
Discuss and Explain!!!

16. packaged DNA found in the nucleus of all eukaryotic cells
5. Chromosomes are:
packaged DNA
found in the nucleus of all eukaryotic cells

17. 6. All species have a set number of chromosomes.
Humans= 46 chromosomes (23 pairs)
Fruit fly= 8 chromosomes
Rice = 12 chromosomes
Dog= 72 chromosomes
Yeast= 32 chromosomes
Goldfish= 100 chromosomes

18. Which of the following would correspond to DNA, genes and chromosomes
Which of the following would correspond to DNA, genes and chromosomes? Alphabet Sentence Words