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Standard Biology Ch. 28 DNA- Life’s Code

Standard Biology Ch. 28 DNA- Life’s Code. 28.1 The DNA Molecule. DNA. DNA is the chemical that makes up your genes. Genes make up your chromosomes. Genes determine your traits. Chromosomes are located in the nucleus of cells. DNA Structure. DNA- deoxyribonucleic acid

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Standard Biology Ch. 28 DNA- Life’s Code

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  1. Standard Biology Ch. 28 DNA- Life’s Code 28.1 The DNA Molecule

  2. DNA • DNA is the chemical that makes up your genes. • Genes make up your chromosomes. • Genes determine your traits. • Chromosomes are located in the nucleus of cells.

  3. DNA Structure • DNA- deoxyribonucleic acid • All living things have DNA • Built like a ladder

  4. DNA Structure • Sides are alternating sugar (deoxyribose) and phosphate • Rungs are nitrogen bases (4 types) • A= adenine • T= thymine • C= cytosine • G= guanine • Base pairing rules: A goes with T and C goes with G

  5. Seven Features of DNA • DNA has 2 sides like the up right part of a ladder • Sides are made of sugar and phosphate • There are parts that connect the sides of the ladder (like “rungs”) • The “rungs” are the nitrogen bases • The four nitrogen bases are A, T, C, and G • A goes with T and C goes with G • DNA is a twisted ladder called a double helix

  6. DNA and Chromosomes • DNA is in every cell of your body and is the same in every cell • Your DNA is different from every other person’s DNA (except identical twins) • DNA is located in the nucleus and makes up genes and chromosomes

  7. Proof that DNA Controls Traits

  8. Proof that DNA Controls Traits • Transformation • DNA from the harmful dead bacteria got into the harmless live bacteria and made the harmless bacteria able to cause pneumonia and kill the mice (Fig. 28-4 p. 590)

  9. How DNA Works • Works like a computer- reads a signal then transfers to a type of protein • DNA is a base code (3 base code) of nitrogen bases

  10. How DNA Works • Normal red blood cells: GAGTGAGGCTTC CTCACTCCGAAG • Sickle cell disease red blood cells: GAGTGAGGCTAC CTCACTCCGATG • Slightly different order of base pairs and codes for a different protein giving a different trait

  11. Making Proteins • DNA directs the making of proteins in a cell • DNA stays in the nucleus and proteins are made in the cytoplasm at ribosomes

  12. DNA to RNA to Protein • Two step process: transcription and translation • Transcription (rewrite): RNA is made from DNA; occurs in the nucleus • Translation (change language): protein is made from RNA code; occurs in the cytoplasm at the ribosome

  13. Making Proteins • RNA is the helper molecule for DNA to make protein • RNA acts like a messenger and carries the code from the DNA to the ribosome

  14. Making Proteins • Each 3 nitrogen bases is a codon (Like a word) • Each codon has meaning as an amino acid

  15. Making Proteins • There are 20 different amino acids, the order of the amino acids gives us all our different

  16. How DNA Copies Itself • DNA needs to be copied before cell division can take place (both mitosis and meiosis) Fig. 28-8 p. 594)

  17. How DNA Copies Itself • DNA untwists • DNA unzips • Loose nitrogen bases with a sugar and phosphate fill in on open middle section following base pairing rules (A=T and C=G) • 2 new DNA are formed that are exactly alike REPLICATION

  18. How DNA Copies Itself

  19. Standard Biology Ch. 28 DNA- Life’s Code 28.2 How the Genetic Message Changes

  20. Mutations • Change in copying the DNA message • Wrong T, C, A, or G then get the wrong protein made and a different trait • Sickle cell disease- change of T to A • Hemophilia- mutation in sex cell of mother

  21. Mutations • Causes of mutations • Copying mistakes • Radiation- X rays and sun’s UV • Chemicals- tobacco, benzene, asbestos and others

  22. Cloning • Have same exact genes and DNA

  23. Identical twins: egg 1 + sperm 1 fertilized egg 1 baby baby Fraternal twins: egg 1 + sperm 1 egg 2 + sperm 2 fertilized egg 1 fertilized egg 2 baby baby Twins

  24. Steps Needed to Clone a Frog • Light frog A- egg cell with nucleus removed • Dark frog B- nucleus from cell of intestine • Add together- get genetic clone of the dark frog (Fig. 28-12 p. 599)

  25. Plant and Animal Breeding • Getting the traits we want

  26. Plant and Animal Breeding • Breeding- bringing together 2 living things to produce offspring (plants and animals) • Most crops and livestock today are produced by selective breeding

  27. Splicing Genes and Gene Therapy • Splice means to insert • Splicing genes mean to add or insert one gene from one organism into another organism

  28. Splicing Genes and Gene Therapy

  29. Splicing Genes and Gene Therapy • Gene therapy is the adding of a healthy gene into a person suffering from a genetic disorder • Cystic fibrosis • Hemophilia

  30. Splicing Genes and Gene Therapy • Recombinant DNA is formed when DNA from one organism is inserted into another organism

  31. Splicing Genes and Gene Therapy • Today use recombinant DNA to produce many vitamins, adhesives, and drugs

  32. Splicing Genes and Gene Therapy • Insulin- human gene for insulin added to bacteria so that the bacteria produce human insulin for people with diabetes Insulin Production for Persons with Diabetes

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