1. Genetic/Hereditary Material (DNA)
Standard: S7L3a – Explain the role of genes and chromosomes in the process of inheriting a specific trait.
Essential Question – What is genetic/hereditary material (DNA)?
Warm-up – Discuss with your partner what you already know about DNA.

2. DNA = Deoxyribose Nucleic Acid
The Blueprint For Life

3. What do we already know about DNA?
It is found in the nucleus
DNA makes up chromosomes
It is the hereditary material for all cells
Eukaryotes AND prokaryotes contain DNA, although prokaryotes do not have a nucleus

4. Chromosomes and DNA
GENES-sections of DNA that contain instructions for characteristics
Our genes are on our chromosomes.
Chromosomes are made up of DNA.
{Ask students where the chromosomes are in this picture. Or ask them where the DNA is. Remind them that the mitochondria also have DNA.}
CHROMOSOMES

5. DNA
In humans, the DNA molecule, if fully extended, would have a total length of 1.7 meters. If you unwrap all the DNA you have in all your cells, you could reach the moon times!

6. DNA by the numbers The average human has 75 trillion cells.
DNA has a diameter of only m. If you unravel all the DNA in the chromosomes of just ONE of your cells, it would stretch out 2 meters.
The earth is 150 billion m, or 93 million miles from the sun.
If you unravel all the DNA in the chromosomes of ALL of your cells, it would stretch from here to the sun more than 400 times!
If you unravel all the DNA in the chromosomes of one of your cells, it would stretch out 2 meters. If you did this to the DNA in all your cells, it would stretch from here to sun more than 400 hundred times!

7. The Double Helix - Discovery
Watson and Crick = scientists that discovered the shape of DNA IN 1953
Franklin = Contributed to discovery with X-ray photo of molecule in 1952

8. DNA Structure 3 PARTS OF DNA Nucleotide = Sugar = Deoxyribose
Phosphate
Nitrogen Base
*Nucleotides link with sugar & phosphates alternating and bases sticking out in middle

9. DNA Structure- Nitrogen Bases
4 bases of DNA (GCAT):
1.Guanine (G)
2.Cytosine (C)
3.Adenine (A)
4.Thymine (T)

10. Complimentary Bases
Two Strands are held together by the bases in the middle.
G & C always bond.
A & T always bond

11. Important: Adenine and Thymine always join together A T
Cytosine and Guanine always join together
C G

12. DNA is a series of nucleotides connected together
COMPONENTS

13. The Double Helix = Shape of DNA: 2 sides of Nucleotides,` link in the middle at the bases, then twist

14. Partial chemical structure
DNA Models
Hydrogen bond
Ribbon model
Partial chemical structure
Computer model
Figure 10.3D

15. DNA Replication Occurs during Interphase
DNA makes an exact copy of itself
Occurs in the nucleus of the cell
Why is this necessary?

16. DNA Replication-STEPS
DNA separates or unzips
Nucleotides pair with bases on old chain
G-C A-T
Two strands created: ½ is the OLD strand; ½ is the NEW strand.

17. Exact copies of original DNA
Unzipped DNA And Replication Of DNA
Exact copies of original DNA
Figure 10.4B

18. Complete The 2nd Strand Of DNA From Replication
A A T T T G C C G G A T A C G -OLD
T T A A A C G G C C T A T G C -NEW
T T T G G C A T T G A T C G C C -OLD
A A A C C G T A A C T A G C G G -NEW
A T A C G A C T T T A A A G G T -OLD
-NEW
T T A G C A T T A G C A T A T T -OLD
G G G C C C A A A T T T C A T -OLD