1. Introduction to DNA

2. Question: From your on-line computer activity, what do you know about the structure of DNA?

3. Structure of DNA DNA is a polymer of what????

4. Nuclotides!

5. There are two types of bases: Adenine & Guanine ( A & G ) = Thymine & Cytosine ( T & C) =

6. There are two types of bases:

7. Intro to DNA Chromosomes exist in “matching pairs” in the nucleus of a cell Scientists call the matching pairs “homologous pairs”. In every human body cell, there are 23 homologous pairs of chromosomes.

8. Example of a human Karyotype IN HUMANS Pair # 1- 22 = “autosomes” Pair #23 = “Sex chromosomes” * XX = * XY =

9. Karyotype What does the prefix “homo” mean? How are homologs similar? #1 #2 #3 #4

10. Karyotype Q: How are homologs different???? GENE – A:

11. IMPORTANT !! All 46 chromosomes are present in every human body cell!!!  Therefore All 30,000 genes pairs which make up a human are in every human body cell!

12. IMPORTANT !! Genome – *** Every body cell of an organism contains its entire genome !!!! *****