Lesson 124 Learning Goal: (You should be able to…) Describe the structure of DNA … the genetic code : (Can you …) Create a piece of DNA

In your binder lesson 124 Description of the structure of DNA (Complimentary pairs of bases, anti parallel strands, twisted double helix, backbones, sequence) Nucleotides A C G T

Essential Questions 1.How do living organisms pass on their traits? 2.How do the laws of genetics help predict the possible expression of certain traits? 3.How do malfunctions affect the system of inheritance?

DNA Vocabulary DNA and replication Chromosome Gene Nucleotide bases, A, C, G, T Double helix Anti parallel strands Codon, Triplet of bases Karyotype

Write to Think What did you learn on Friday about the genetic code? What is it? 2.What is a mutation? 3.Is a mutation good, bad or neutral? Explain.

Plan of action 1.Direct instruction about the structure of DNA 2.Make a nucleotide base 3.Pair up (complimentary) 4.Create a class piece of DNA 5.Describe the structure of DNA – Definitions – Sentences – Questions

Twisted Ladder Double Helix

Bases

Base-Pair Rules C and G always go together 3 hydrogen bonds A and T always go together 2 hydrogen bonds A T GC

The DNA Ladder phosphate group DR sugar molecule Base Pairs Anti parallel strands Complimentary

Twisted Ladder Double Helix

Your Turn to model DNA Make a base Now pair up with your compliment! Now make a DNA strand!

DNA structure terms Nucleotide Bases A, C, G, T Complimentary base pairs, (A with T, C with G) Sequence = gene Complimentary strands Anti parallel strands (Twisted) “Ladder” Double helix

Write sentences connecting the following words: 1.Nucleotide, base, A, C, G, T 2.Base A, base T, complimentary 3.Nucleotides, sequence, strand 4.Complimentary, strands, anti parallel 5.Complimentary, strands, twisted ladder, double helix 6.Gene, nucleotide sequence, complimentary strand, DNA, chromosome

Answer the following: 1.Nucleotides can only pair up in a particular way. Explain why? 2.DNA has two complimentary stands. What does this mean? 3.What is a double helix? 4.Why is DNA sometimes described as a twisted ladder? 5.Why do you think DNA is a double helix rather than just a ladder structure? What advantage or function does a helix have over a ladder? 6.Where is the genetic code in the DNA double helix?

Animations!!! The purpose … To take some notes on the structure, function and organization of DNA so that you can … Write a paragraph that describes how the structure of DNA is related to its function

Source for lots of video clips! I think this is the DVD on line? helix helix

Summarizer Describe structure and function of DNA.

End of Lesson