2. Genetics

3. Segments of a chromosome (DNA) that provide instructions for protein synthesis different forms/versions of a gene I. Introduction Alleles: Genes: Trait: A characteristic produced by an organism’s _______ proteins Chromosome:Super-coiled DNA  DNA only coils into dense chromosomes during Mitosis & Meiosis

5. A. Gregor Mendel: pea plants Austrian monk who studied heredity in ____________ “The Father of Genetics”

6. B. Thomas Morgan chromosome * He called them 1) Morgan noticed that many traits were almost always inherited together. 2) Concluded that some genes are located on the same ______________ and tend to be inherited together. * Exception: I love fruit… OMG! Me too! I love fruit flies. and I love flies. linked genes Crossing Over (during meiosis)

7. Crossover Frequency ABCD Crossing over will disrupt linkage between _______ more often than _______ A & B C & D

8. 1. Franklin & Wilkins (1950s): Used x-ray crystallography to produce “images” of DNA. C. Discovering the Structure of DNA

9. 2. Watson and Crick (1953): With the help of Franklin’s x-rays, they discovered and built a model of DNA’s ________________structure. In 1962, Watson, Crick and Wilkins received a Nobel Prize for their work. *Franklin died before the award was given. double helix

11. Hey, Watson! Yes, Crick? Isn’t it awesome that we have a Nobel Prize with Wilkins??? Yup. Are you guys talking about me? I feel left out.

12. X

13. A. DNA Structure 1. DNA is a large molecule made up of many nucleotides 2. Nucleotides consist of 3 parts: a) 1 Sugar (deoxyribose) b) 1 Phosphate group c) 1 Nitrogenous base “Backbone” (Adenine, Thymine, Cytosine, Guanine) 3. The double helix looks like a twisted ladder a)The 2 strands are held together by ________________ between the base pairs b) Base pairing:“AT Glen Cove” (A-T ; G-C) *giggle* II. DNA Structure & Replication Hydrogen bonds

14. phosphate sugar base A T C G C G

15. AGCATGGAGCATGG TCGTACCTCGTACC T C G TA C CCGAG G T A DNA Polymerase DNA Polymerase Template Strand Template Strand

16. B. DNA Replication 1. Enzymes “unzip” the double helix * Multiple enzymes are involved in replication a) Hydrogen bonds between base pairs are broken 2. Each original strand serves as a template 3. DNA polymerase enzymes attach free- floating nucleotides to their base pairs on each template 4. Result: 2 identical strands of DNA

17. AGCATGGAGCATGG TCGTACCTCGTACC T C G TA C CCGAG G T A DNA Polymerase DNA Polymerase Template Strand Template Strand

18. A C C T A G T G

19. Link

20. III. Protein Synthesis * Ribosomes produce proteins.  They can’t read DNA, so the genetic code must be transferred to __________________ messenger RNA

21. AGCATGGAGCATGG TCGTACCTCGTACC U C G UA C C RNA Polymerase Template Strand

22. A. Transcription (mRNA synthesis): * In RNA, Uracil replaces Thymine (NO T’s!!!). 4. The newly formed mRNA molecule detaches from the template and the DNA “zips up” again. * The mRNA’s code is written in codons – groups of 3 base pairs 1. Enzymes “unzip” the double helix a) Hydrogen bonds between base pairs are broken 2. Only one of the original strands serves as a template 3. RNA polymerase enzymes attach free- floating nucleotides to their base pairs on the template

23. AGCATGGAGCATGG TCGTACCTCGTACC U C G UA C C RNA Polymerase Template Strand

26. B. Translation (decoding mRNA to make a protein) 1) mRNA leaves the nucleus and goes to a ribosome 2) The ribosome reads the mRNA codons (groups of 3 bases) *Each codon calls for a specific amino acid 3) The amino acids are bonded together 4) This process repeats until the protein is complete.

28. Protein Synthesis Animation http://www.wisc- online.com/objects/index_tj.asp?objID=AP1302

30. Example Problem DNA = TACGCCTAAATC Amino Acids: Start (Methionine) – Arginine – Isoleucine - Stop Codons: AUG CGG AUU UAG mRNA = AUGCGGAUUUAG

31. Sample Problem DNA = TACTAACGGATT Find mRNA, separate into codons, and find the corresponding amino acids to make a protein.

32. DNA = TACTAACGGATT Amino Acids: M et(Start) – Ile – Ala - Stop Codons: AUG AUU GCC UAA mRNA = AUGAUUGCCUAA

33. IV. Gene Regulation and Environmental Influence

34. A. Gene Regulation and Environmental Influence 1) In both prokaryotes and eukaryotes, only some of the genes in a cell are working at a given time. a) This is why a multicellular eukaryote (like you) is composed of many different types of cells – all with the same DNA. b) Cell differentiation (during embryonic development) activates specific gene sequences in the different cell types. Ex. The active genes in a cardiac cell are not all the same as those in a liver cell.

36. E. Gene Regulation and Environmental Influence 1) In both prokaryotes and eukaryotes, only some of the genes in a cell are working at a given time. a) This is why a multicellular eukaryote (like you) is composed of many different types of cells – all with the same DNA. b) Cell differentiation (during gastrulation) activates specific gene sequences in the different cell types. 2) Environmental conditions may influence the expression of genes. Ex. Exposure to sunlight = tanning (increase in production of the pigment melanin). a)Certain genes may be “turned on” or simply transcribed more often in the presence of particular chemical or physical stimuli. Ex. Fur color of the arctic rabbit Ex. The active genes in a cardiac cell are not all the same as those in a liver cell.

41. V. Gene Mutations: 1.Mutation- 2. Mutations may be caused by errors in replication or by mutagens. Mutagen- may lead to the production of an abnormal protein. 3. If a mutation occurs __________, it may be transmitted to offspring. a change in the genetic material of a cell. a physical or chemical agent that causes mutations in DNA. in a gamete

42. Types of Gene Mutations Examples: Substitution: May or may not alter the amino acid sequence. Example: Normal DNAMutated DNA TAC GCA TGG AAT TAC GTA TGG AAT AUG CGU ACC UUAmRNA: MetArgThrLeu AUG CAU ACC UUA MetThrLeuHis DNA: substitution The replacement of a nucleotide by another one.

44. Example: Insertion Normal DNAMutated DNA TAC GCA TGG AAT TAT CGC ATG GAA T AUG CGU ACC UUAmRNA: MetArgThrLeu AUA GCG UAC CUU A Ile TyrLeuAla DNA: Frameshift Mutations: Very dramatic results insertion shift The insertion or deletion of nucleotides in the DNA sequence causing all other nucleotides to shift (this changes the codons).

45. Sickle-Cell Anemia a. Autosomal Codominant b. Abnormal hemoglobin causes sickle-shaped red blood cells c. RBC’s carry less oxygen and can clog small blood vessels d. Detected w/ a blood test e. Treated w/ folic acid and medications

48. VI. Chromosome Disorders Detected by karyotypes

49. G. Chromosomal Disorders 1. Errors in cell division may lead to chromosomal damage or a change in chromosomal number. *drastic effects… often lethal

50. a) b) c) A B C D E F G A B C E F G A B C D E F G D Deletion Q R S Duplication Translocation Q R SD A B C D E F GD or

51. Cri Du Chat: deletion on chromosome 5… small head, cat-like cry, mental retardation, facial abnormalities

52. 2. Non-disjunction (change in chromosome number): a) An uneven distribution of chromosomes during cell division (meiosis). b) Results in trisomy: 3 copies (instead of 2) of a chromosome Ex: Down Syndrome- individuals with 3 copies of chromosome 21

55. Ex: Down Syndrome- individuals with 3 copies of chromosome 21 *facial abnormalities, delayed physical, mental, and social development, birth defects

56. Check this out.this

57. Kleinfelters: male w/ extra X chromosome *less muscular body, reduced facial and body hair, possible increase in breast tissue, sterile (infertile)

58. Turner Syndrome: female w/ only 1 X chromosome short stature, swelling of hands and feet, low hairline, low-set ears, webbed necks, sterile (infertile)

59. VII. Genetic Engineering (Traditional): 1.Selective Breeding : allow only organisms with desirable traits to mate Mate Don’t Mate

61. a) Hybridization: Cross two genetically different individuals to bring together the best traits of both organisms

62. The Ultimate Hybridization:

63. b) Inbreeding: The continued breeding of individuals with similar characteristics

64. **Excessive inbreeding can bring together two recessive alleles for a genetic defect

65. VIII. Genetic Engineering (DNA Technology): 1. The Human Genome Project (1990-2003) Identify the 20,000-25,000 genes in human DNA Sequence the 3 billion base pairs in human DNA Store information in database for analyses a) Major Goals:

66. 2. DNA Fingerprinting (Gel Electrophoresis) a)Restriction Enzymes cut DNA into segments at specific base pair sequences (everyone has them in different locations) b) Electrophoresis technique uses electrical current to move DNA through an agarose gel * DNA is negatively charged … moves towards positive side c) Shorter DNA fragments move farther than longer ones d) Since we have unique DNA, our “banding pattern” is also unique

69. longer fragments shorter fragments power source completed gel gel DNA & restriction enzyme wells - +

70. Uses: Forensics Comparing DNA sample from crime scene with suspects & victim – + S1 DNA  S2S3V suspects crime scene sample

72. Uses: Paternity Who’s the father? + DNA  childMomF1F2 –

73. Uses: Medical diagnostic Comparing normal allele to disease allele chromosome with disease-causing allele 2 chromosome with normal allele 1 – + allele 1 allele 2 DNA  Example: test for Huntington’s disease

74. Uses: Evolutionary relationships Comparing DNA samples from different organisms to measure evolutionary relationships – + DNA  13245 12345 turtlesnakeratsquirrelfruitfly

75. 3.Cloning Ex. “Dolly” the sheep

77. AwesomerAwesome

78. Clone Mimi the Mouse Clone a dog http://www.youtube.com/watch ?v=dV2OxSGhwjY

79. 4.Recombinant DNA Restriction Enzymes cut DNA in order to insert a gene or genes into another chromosome or plasmid * Plasmids = rings of DNA found in bacteria (in addition to chromosomes)

80. a) Transgenic Organisms: Genetically engineered organisms containing one or more genes from another species Ex. bacterial cells containing human gene for insulin produce pharmaceutical insulin supplements * process called: transformation

84. d. Gene Therapy: use recombinant DNA technology to produce human cells with “normal” gene to counteract a disorder Ex. Gene therapy in bone marrow cells can be used to improve immunity.

85. Dino VenterOrgans

86. 5. Genetically Modified Organisms (GMOs) a)Formed by artificially… Mutating genes Deleting genes Inserting genes (Transgenics) b) Uses: Medicine/Pharmaceuticals Food crops (more nutritious; pest & drought-resistant) Biofuel crops *Controversial, but everywhere!