1. TOOTHPICK BRIDGE CHALLENGE: Using glue and toothpicks ONLY build a bridge that will support the most weight! Using glue and toothpicks ONLY build a bridge that will support the most weight! Weight will be applied by attaching two hooks and suspending in from the midpoint of the bridge. Weight will be applied by attaching two hooks and suspending in from the midpoint of the bridge.

2. TOOTHPICK BRIDGE CHALLENGE: Bridges will be tested in 24 hours Bridges will be tested in 24 hours You have 20 minutes to complete your task You have 20 minutes to complete your task Winning group receives candy! Winning group receives candy!

3. TOOTHPICK BRIDGE CHALLENGE: What role did structure play in the amount of weight that a toothpick bridge can support? What role did structure play in the amount of weight that a toothpick bridge can support? Structure plays a role in supporting life, too… Structure plays a role in supporting life, too…

4. DNA & Genes Lecture #1 (12.1)

5. I. WHAT DOES DNA LOOK LIKE? A. DNA is made up of a long chain of _________________. 1. Nucleotide- Subunit of DNA a. 1 Simple Sugar (dioxyribose) b. 1 Phosphate Group c. 1 _____________________

6. A Free Nucleotide Phosphate sugarsugar Guanine (Nitrogen Base)

7. B. Nitrogen Bases 1. Adenine (A) 2. _______ (T) 3. _______ (C) 4. Guanine (G) I. WHAT DOES DNA LOOK LIKE? Always Pair Up

8. I. WHAT DOES DNA LOOK LIKE? DNA PICTURE The side is made of ________ & phosphate The side is made of ________ & phosphate Nitrogen bases bonded in the middle by a ________ bond Nitrogen bases bonded in the middle by a ________ bond

9. I. WHAT DOES DNA LOOK LIKE? C. __________________ Model 1. Proposed by Francis Crick & James Watson in 1954 2. Means: 2 sided stand, twisted 3. Looks like a ______________

11. II. WHAT IS DNA? A. DNA 1. Short for “deoxyribonucleic acid” 2. The genetic code that contains instructions to build _________ __________________________ __________________________

12. II. WHAT IS DNA (cont.) B. Proteins- Polymer that provides structure for _______ and ________ 1. Different proteins cause different traits to appear C. Enzymes- Specialized proteins responsible for chemical reactions 1. Necessary for ______, _______, _________, etc

13. III. NUCLEOTIDE SEQUENCE A. The order of the nitrogen bases determines what ____________ B. The more alike the nucleotide sequence, the more closely related the ____________ 1. Provides evidence of evolution

14. IV. DNA Replication A. Before a cell can enter ______ or _______ it must duplicate its DNA so that each daughter cell will get its share of DNA. B. DNA Replication- Making an exact copy of DNA.

16. IV. DNA Replication (cont) 1. Separation of Strands a. An ______ splits the nucleotide pairs (unzips the zipper) b. The bases are ___________ 2. Base Pairing a. Free nucleotide bases pair up with the ___________ exposed bases

17. IV. DNA Replication (cont) 3. Bonding of Bases a. The new bonds are ________ between nucleotides b. 2 strands are formed connected by a ________ (This makes the chromosome appear as an X)

18. DNA Replication Reenactment Using the materials provided, You have 5 minutes to decide how to model the steps of DNA replication. Using the materials provided, You have 5 minutes to decide how to model the steps of DNA replication.

19. V. REVIEW What is DNA? What is DNA? Why proteins important? Why proteins important? Why are enzymes important? Why are enzymes important? What is the complimentary bases for AATGCCGTA? What is the complimentary bases for AATGCCGTA? Who proposed the double helix model of DNA? Who proposed the double helix model of DNA?

20. V. REVIEW What are the 3 steps of DNA replication? What are the 3 steps of DNA replication?

21. The Answer… DNA MUTATIONS!!! 1) Mutations occur in the DNA of an organism. 2) If the mutation doesn’t kill the organism, it can be passed on to the offspring! 3) This is the basis for ALL variation in organisms today!