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University of California accessed 07.04.08 Chromosomes, Genes, Alleles Chromosomes, Genes, Alleles.

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Presentation on theme: "University of California accessed 07.04.08 Chromosomes, Genes, Alleles Chromosomes, Genes, Alleles."— Presentation transcript:

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2 University of California http://www.ipm.ucdavis.edu/NEWS/aromatherapy-news.html accessed 07.04.08 Chromosomes, Genes, Alleles Chromosomes, Genes, Alleles Meiosis Theoretical Genetics Theoretical Genetics Genetic Engineering Genetic Engineering

3 Europa http://ec.europa.eu/research/quality-of-life/arabidopsis.html accessed 07.04.08 A. Chromosomes A. Chromosomes B. Genes and Alleles B. Genes and Alleles C. Mutations C. Mutations

4 A. Chromosomes 1. Eukaryote chromosomes are made of DNA and protein 2. DNA usually exists in the nucleus as chromatin “string” a. before cells divide DNA duplicates & condenses (chromosome)_ author unknown address unknown accessed unknown

5 b. chromosomes resemble “balls of string” c. sister chromatids joined at the centromere_ author unknown address unknown accessed unknown

6 b. chromosomes resemble “balls of string” c. sister chromatids joined at the centromere_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

7 1. Gene- a heritable factor that controls a specific characteristic 2. Allele- one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene 3. Genome- the whole of the genetic information of an organism_ B. Genes and Alleles author unknown address unknown accessed unknown

8 C. Mutations 1. A gene mutation is any change in the nucleotide sequence of DNA 2. The most common types are base substitution, insertion, or deletion a. The dog and cat are fun. b. The dog and bat are fun. c. The dop gan dca tar efu n. d. The dga ndc ata ref un. 3. Caused by mutagens: copying error, chemicals, or radiation_ Play author unknown address unknown accessed unknown

9 4. Sickle cell anemia results from a base substitution mutation in the gene for hemoglobin which is reflected through the processes of transcription and translation a. GAG has mutated to GTG causing glutamic acid to be replaced by valine b. the altered amino acid sequence causes hemoglobin proteins to polymerize forming chains_ University of Massachusetts Medical School http://www.umassmed.edu/bmp/graphics/royer_figC.gif accessed 17-02-07

10 c. hemoglobin chains deform the red blood cells, hence sickle cell anemia_ author unknown address unknown accessed unknown

11 5. The frequency of the sickle cell allele coincides with the distribution of malaria a. carriers of the trait are resistant to malaria_ Discover http://www.discover.com/images/issues/mar-05/gene-map.jpg accessed 17-02-07

12 5. The frequency of the sickle cell allele coincides with the distribution of malaria a. carriers of the trait are resistant to malaria_ Discover http://www.discover.com/images/issues/mar-05/gene-map.jpg accessed 17-02-07 author unknown address unknown accessed unknown author unknown address unknown accessed unknown

13 5. The frequency of the sickle cell allele coincides with the distribution of malaria a. carriers of the trait are resistant to malaria_ Discover http://www.discover.com/images/issues/mar-05/gene-map.jpg accessed 17-02-07 author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click WHERE A CORRELATION IS FOUND, A CAUSAL LINK MAY OR MAY NOT BE PRESENT. THE FREQUENCY OF THE SICKLE-CELL ALLELE IS CORRELATED WITH THE PREVALENCE OF MALARIA IN MANY PARTS OF THE WORLD. IN THIS CASE, THERE IS A CLEAR CAUSAL LINK. OTHER CASES WHERE THERE IS NO CAUSAL LINK COULD BE DESCRIBED AS A CONTRAST. THERE HAS CLEARLY BEEN NATURAL SELECTION IN FAVOUR OF THE SICKLE- CELL ALLELE IN MALARIAL AREAS, DESPITE IT CAUSING SEVERE ANEMIA IN THE HOMOZYGOUS CONDITION. NATURAL SELECTION HAS LED TO PARTICULAR FREQUENCIES OF THE SICKLE CELL AND THE NORMAL HEMOGLOBIN ALLELES, TO BALANCE THE TWIN RISKS OF ANEMIA AND MALARIA. WHERE A CORRELATION IS FOUND, A CAUSAL LINK MAY OR MAY NOT BE PRESENT. THE FREQUENCY OF THE SICKLE-CELL ALLELE IS CORRELATED WITH THE PREVALENCE OF MALARIA IN MANY PARTS OF THE WORLD. IN THIS CASE, THERE IS A CLEAR CAUSAL LINK. OTHER CASES WHERE THERE IS NO CAUSAL LINK COULD BE DESCRIBED AS A CONTRAST. THERE HAS CLEARLY BEEN NATURAL SELECTION IN FAVOUR OF THE SICKLE- CELL ALLELE IN MALARIAL AREAS, DESPITE IT CAUSING SEVERE ANEMIA IN THE HOMOZYGOUS CONDITION. NATURAL SELECTION HAS LED TO PARTICULAR FREQUENCIES OF THE SICKLE CELL AND THE NORMAL HEMOGLOBIN ALLELES, TO BALANCE THE TWIN RISKS OF ANEMIA AND MALARIA. Theory of Knowledge TOK

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15 D. Chromosomal Accidents D. Chromosomal Accidents author unknown address unknown accessed unknown A. Karyotyping A. Karyotyping B. Homologous Chromosomes B. Homologous Chromosomes C. Meiosis C. Meiosis

16 1. The display of the chromosomes is called a karyotype 2. Karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities a. in karyotyping, chromosomes are arranged in pairs according to their size and structure_ Play author unknown address unknown accessed unknown A. Karyotyping

17 1. Each chromosome has a twin referred to as a homologous chromosome a. homologous pairs contain the same gene loci in the types of genes b. the genes may have different versions of the same trait, alleles (eyes: blue/brown) c. contain the same gene loci in the same sequence which are capable of pairing up to form bivalents during prophase I of meiosis_ author unknown address unknown accessed unknown B. Homologous Chromosomes

18 2. Diploid cells (2n) have two sets of homologous chromosomes a. humans body cells (46) b. 23 homologous pairs (numbered 1-23) c. one set from each parent d. pair #23 are the sex chromosomes 1) female- XX 2) male- XY_ author unknown address unknown accessed unknown

19 2. Diploid cells (2n) have two sets of homologous chromosomes a. humans body cells (46) b. 23 homologous pairs (numbered 1-23) c. one set from each parent d. pair #23 are the sex chromosomes 1) female- XX 2) male- XY_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown

20 2. Diploid cells (2n) have two sets of homologous chromosomes a. humans body cells (46) b. 23 homologous pairs (numbered 1-23) c. one set from each parent d. pair #23 are the sex chromosomes 1) female- XX 2) male- XY_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

21 3. Haploid cells (n) have one set of chromosomes a. human sex cells (23) 4. When two sex cells (gametes) are joined (fertilization) a zygote is formed_ author unknown address unknown accessed unknown

22 1. Meiosis is a reduction division of diploid nuclei to form a haploid nuclei_ C. Meiosis author unknown address unknown accessed unknown

23 C. Meiosis 1. Meiosis is a reduction division of diploid nuclei to form a haploid nuclei_ author unknown address unknown accessed unknown Leif Austenberg Click

24 2. Meiosis I: pairing and separation of homologous chromosomes a. prophase I: condensing of chromosomes, crossing over* between homologous pairs, spindle microtubules form, nuclear membrane breaks down *exchange of genetic material between non-sister chromatids_ author unknown address unknown accessed unknown

25 2. Meiosis I: pairing and separation of homologous chromosomes a. prophase I: condensing of chromosomes, crossing over* between homologous pairs, spindle microtubules form, nuclear membrane breaks down *exchange of genetic material between non-sister chromatids _ Play author unknown address unknown accessed unknown lord bacon 4 http://drlordbacon4.blogspot.com/ accessed 16.04.08 lord bacon 4 http://drlordbacon4.blogspot.com/ accessed 16.04.08 Click

26 b metaphase I: spindle microtubules attach to chromosomes, homologous pairs line up on the equator c. anaphase I: chromosome number is halved when homologous pairs separate to opposite poles (sister chromatids are still attached) d. telophase I: homologous pairs (sometimes) relax, nucleus reforms, cell is divided to form two new cells which immediately begin to divide again_ author unknown address unknown accessed unknown

27 3. Meiosis II (similar to mitosis): separation of sister chromatids a. prophase II: condensing (sometimes) of sister chromatids, new spindle microtubules begin to grow b metaphase II: sister chromatids line up_ author unknown address unknown accessed unknown

28 c. anaphase II: sister chromatids separate when centromeres are divided d. telophase II: sister chromatids relax, nucleus reforms, cell divides into two cells with half the genetic information of the parent_ Play author unknown address unknown accessed unknown

29 D. Chromosomal Accidents 1. Occasionally one or more pairs of chromosomes fail to separate correctly 2. Non-disjunction can lead to changes in chromosome number a. normal human sex cells contain 23 chromosomes b. some gametes contain extra, 24 chromosomes (sometimes survive) c. other gametes contain too few, 22 chromosomes (often die)_ author unknown address unknown accessed unknown

30 D. Chromosomal Accidents 1. Occasionally one or more pairs of chromosomes fail to separate correctly 2. Non-disjunction can lead to changes in chromosome number a. normal human sex cells contain 23 chromosomes b. some gametes contain extra, 24 chromosomes (sometimes survive) c. other gametes contain too few, 22 chromosomes (often die)_ author unknown address unknown accessed unknown VARIOUS QUESTIONS RELATING TO KARYOTYPING COULD BE RAISED, INCLUDING BALANCING THE RISKS OF SIDE-EFFECTS (FOR EXAMPLE, MISCARRIAGE), AGAINST THE POSSIBILITY OF IDENTIFYING AND ABORTING A FETUS WITH AN ABNORMALITY. THERE ARE QUESTIONS ABOUT DECISION-MAKING: WHO SHOULD MAKE THE DECISION ABOUT WHETHER TO PERFORM KARYOTYPING AND ALLOW A SUBSEQUENT ABORTION—PARENTS OR HEALTH-CARE PROFESSIONALS OR BOTH GROUPS? THERE ARE ALSO QUESTIONS ABOUT WHETHER OR NOT NATIONAL GOVERNMENTS SHOULD INTERFERE WITH PERSONAL FREEDOMS, AND WHETHER OR NOT THEY SHOULD BE ABLE TO BAN PROCEDURES WITHIN THE COUNTRY AND POSSIBLY ALSO BAN CITIZENS TRAVELLING TO FOREIGN COUNTRIES WHERE THE PROCEDURES ARE PERMITTED. Theory of Knowledge TOK Play

31 3. Trisomy (three chromosomes of one type) accounts for a number of abnormalities a. Down’s syndrome (trisomy 21) results from an extra chromosome 21 b. chromosome 21 fails to separate in meiosis II c. egg cell caries two copies of chromosome 21 d. egg containing 24 chromosomes fuses with sperm containing 23_ author unknown address unknown accessed unknown

32 e. karyotypes detecting Down’s syndrome will display three copies of chromosome 21_ author unknown address unknown accessed unknown

33 4. Down’s syndrome occurs in about 1 in 700 births_ author unknown address unknown accessed unknown

34 2. Down’s syndrome occurs in about 1 in 700 births_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

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36 flickr http://www.flickr.com/photos/meantux/256130968/ accessed 11.04.08 A. The Language of Genetics A. The Language of Genetics B. Monohybrid Cross B. Monohybrid Cross C. Codominance/Multiple Alleles C. Codominance/Multiple Alleles E. Pedigrees E. Pedigrees D. Sex-Linkage D. Sex-Linkage

37 A. The Language of Genetics 1. Gene- a portion of the chromosome that controls a trait (flower color) a. locus- the particular position on homologous chromosomes of a gene 2. Allele- different versions of a gene (P- purple or p- white) a. genotype- the alleles of an organism (PP, Pp, pp) b. phenotype- the characteristics of an organism (purple or white)_ California State University, Long Beach http://www.csulb.edu/~kmacd/361-6-Ch2.htm accessed 22.04.08

38 3. True-breed- an organism that always passes on its characteristics a. homozygous- having two identical alleles of a gene (PP- purple or pp- white) 4. Hybrid- an organism that has two different alleles for the same trait a. heterozygous- having two different alleles of a gene (Pp- purple)_ author unknown address unknown accessed unknown

39 5. Dominant allele- an allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous form (P- purple) 6. Recessive allele- an allele that only has an effect on the phenotype when present in the homozygous state (p- white) 7. Codominant alleles- pairs of alleles that both affect the phenotype when present in a heterozygote_ author unknown address unknown accessed unknown

40 5. Dominant allele- an allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous form (P- purple) 6. Recessive allele- an allele that only has an effect on the phenotype when present in the homozygous state (p- white) 7. Codominant alleles- pairs of alleles that both affect the phenotype when present in a heterozygote_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

41 8. Carrier- an individual that has one copy of a recessive allele that causes a genetic disease in individuals that are homozygous for this allele 9. Test cross- testing a suspected heterozygote by crossing it with a known homozygous recessive 10. P Generation- parents 11. F 1 Generation- children 12. F 2 Generation- grandchildren_ Trek Earth http://www.trekearth.com/gallery/Oceania/New_Zealand/photo248461.htm accessed 11-03-07

42 B. Monohybrid Cross 1. A monohybrid cross results from crossing two organisms that differ in one characteristic 2. How to solve genetic problems using a punnett square a. identify the dominant and recessive alleles b. determine and label the parental genotypes and possible gametes c. set up a Punnett square with the sperm along the top and the eggs along the side_ author unknown address unknown accessed unknown Play

43 d. cross by placing the alleles from each sperm in the boxes below and the alleles from each egg in the boxes to the right e. the resulting combinations are the genotypes of the offspring (label this) f. determine the phenotypes of the offspring and list in each box (label this) g. determine the solution to the problem_ author unknown address unknown accessed unknown Think

44 d. cross by placing the alleles from each sperm in the boxes below and the alleles from each egg in the boxes to the right e. the resulting combinations are the genotypes of the offspring (label this) f. determine the phenotypes of the offspring and list in each box (label this) g. determine the solution to the problem_ author unknown address unknown accessed unknown 1. EXPLAIN WHY ALL THE F 1 GUINEA PIGS HAVE SHORT HAIR. 2. HOW MANY TYPES OF EGG/SPERM WILL THE F 1 GUINEA PIGS PRODUCE? 3. HOW MANY EGGS AND SPERM WILL THE F 1 GUINEA PIGS PRODUCE? 4. HOW MANY GUINEA PIG BABIES ARE PRODUCED IN THE F 2 GENERATION? 5. WOULD IT BE POSSIBLE FOR ALL THE F 2 TO BE LONG HAIRED? …SHORT HAIRED? 6. DRAW PUNNETT SQUARES TO SHOW A CROSS BETWEEN… A. HETEROZYGOTE AND A HOMOZYGOUS LONG HAIRED GUINEA PIG? B. HETEROZYGOTE AND A SHORT HAIRED GUINEA PIG? 1. EXPLAIN WHY ALL THE F 1 GUINEA PIGS HAVE SHORT HAIR. 2. HOW MANY TYPES OF EGG/SPERM WILL THE F 1 GUINEA PIGS PRODUCE? 3. HOW MANY EGGS AND SPERM WILL THE F 1 GUINEA PIGS PRODUCE? 4. HOW MANY GUINEA PIG BABIES ARE PRODUCED IN THE F 2 GENERATION? 5. WOULD IT BE POSSIBLE FOR ALL THE F 2 TO BE LONG HAIRED? …SHORT HAIRED? 6. DRAW PUNNETT SQUARES TO SHOW A CROSS BETWEEN… A. HETEROZYGOTE AND A HOMOZYGOUS LONG HAIRED GUINEA PIG? B. HETEROZYGOTE AND A SHORT HAIRED GUINEA PIG? Think about it! Think

45 C. Codominance/Multiple Alleles 1. Codominant alleles- pairs of alleles that both affect the phenotype when present in a heterozygote a. produces an intermediate phenotype 2. The main letter should relate to the gene and the suffix to the allele, both upper case a. red and white codominant flower colours should be represented as C R and C W, respectively_ author unknown address unknown accessed unknown

46 C. Codominance/Multiple Alleles 1. Codominant alleles- pairs of alleles that both affect the phenotype when present in a heterozygote a. produces an intermediate phenotype 2. The main letter should relate to the gene and the suffix to the allele, both upper case a. red and white codominant flower colours should be represented as C R and C W, respectively_ author unknown address unknown accessed unknown REASONS FOR MENDEL’S THEORIES NOT BEING ACCEPTED BY THE SCIENTIFIC COMMUNITY FOR A LONG TIME COULD BE CONSIDERED. OTHER CASES OF PARADIGM SHIFTS TAKING A LONG TIME TO BE ACCEPTED COULD BE CONSIDERED. WAYS IN WHICH INDIVIDUAL SCIENTISTS ARE MOST LIKELY TO BE ABLE TO CONVINCE THE SCIENTIFIC COMMUNITY COULD BE CONSIDERED, AND ALSO THE NEED ALWAYS TO CONSIDER THE EVIDENCE RATHER THAN THE VIEWS OF INDIVIDUAL SCIENTISTS, HOWEVER DISTINGUISHED. Theory of Knowledge TOK

47 b. for sickle-cell anemia, Hb A is normal and Hb S is sickle cell_ National Institutes of Health http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_Causes.html accessed 13.04.08

48 3. Some genes have more than two alleles (multiple alleles) 4. An example of codominance and multiple alleles is the ABO blood groups_ author unknown address unknown accessed unknown

49 5. There are 4 blood types, A, B, AB, and O a. A (I A ) and B (I B ) are codominant b. the allele for O (i) is recessive to A (I A ) and B (I B ) phenotype-genotype type A- I A I A or I A i type AB- I A I B type B- I B I B or I B i type O- ii_ author unknown address unknown accessed unknown

50 5. There are 4 blood types, A, B, AB, and O a. A (I A ) and B (I B ) are codominant b. the allele for O (i) is recessive to A (I A ) and B (I B ) phenotype-genotype type A- I A I A or I A i type AB- I A I B type B- I B I B or I B i type O- ii_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

51 D. Sex-Linkage 1. In humans the sex chromosomes control gender through the inheritance of X and Y chromosomes a. females- XX b. males- XY 2. Sex linkage- sex chromosomes carry genes for traits_ author unknown address unknown accessed unknown

52 3. Some genes are present on the X chromosome and absent from the shorter Y chromosome a. females have 2 genes for these traits b. males have only 1 gene for each of these traits_ author unknown address unknown accessed unknown

53 4. The inheritance of colour blindness and hemophilia are examples of sex linkage a. both colour blindness and hemophilia are produced by a recessive sex- linked allele on the X chromosome b. X b (colour blindness) and X B (normal) is the notation for the alleles c. X h (hemophilia) and X H (normal) is the notation for the alleles_ Color bind Home Page http://colorvisiontesting.com/ accessed 13. 04.08

54 5. Eye color in fruit flies is also an example of a sex-linked trait (wild type- red is dominant to white) phenotype-genotype female, red-eyed: X R X R female, red-eyed: X R X r female, white-eyed: X r X r male, red-eyed: X R Y male, white-eyed: X r Y_ author unknown address unknown accessed unknown

55 5. Eye color in fruit flies is also an example of a sex-linked trait (wild type- red is dominant to white) phenotype-genotype female, red-eyed: X R X R female, red-eyed: X R X r female, white-eyed: X r X r male, red-eyed: X R Y male, white-eyed: X r Y_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

56 6. A human female can be homozygous or heterozygous with respect to sex-linked genes 7. Female carriers are heterozygous for X-linked recessive alleles phenotype-genotype female, normal: X H X H female, carrier: X H X h female, hemophiliac: X h X h _ National Institutes of Health http://www.nhlbi.nih.gov/health/dci/Diseases/hemophilia/hemophilia_causes.html accessed 13.04.08

57 Think E. Pedigrees 1. The genotypes and phenotypes of individuals can be deduced in pedigree charts a. unshaded square- normal male b. unshaded circle- normal female c. shaded square- affected male d. shaded circle- affected female_ author unknown address unknown accessed unknown

58 E. Pedigrees 1. The genotypes and phenotypes of individuals can be deduced in pedigree charts a. unshaded square- normal male b. unshaded circle- normal female c. shaded square- affected male d. shaded circle- affected female_ author unknown address unknown accessed unknown THE DIAGRAM SHOWS A PEDIGREE OF A FAMILY WITH RED-GREEN COLOUR BLINDNESS, A SEX-LINKED TRAIT. 1. WHAT IS THE GENOTYPE OF THE MAN IN GENERATION 1? 2. WHAT ALLELE DOES HE GIVE TO EACH OF HIS DAUGHTERS? …SONS? 3. WHAT IS THE GENOTYPE OF THE WOMAN IN GENERATION 1? 4. WHAT ALLELE DID SHE GIVE TO EACH OF HIS DAUGHTERS? …SONS? 5. ARE THERE ANY INDIVIDUALS WHOSE GENOTYPE CANNOT BE DETERMINED USING THIS PEDIGREE? THE DIAGRAM SHOWS A PEDIGREE OF A FAMILY WITH RED-GREEN COLOUR BLINDNESS, A SEX-LINKED TRAIT. 1. WHAT IS THE GENOTYPE OF THE MAN IN GENERATION 1? 2. WHAT ALLELE DOES HE GIVE TO EACH OF HIS DAUGHTERS? …SONS? 3. WHAT IS THE GENOTYPE OF THE WOMAN IN GENERATION 1? 4. WHAT ALLELE DID SHE GIVE TO EACH OF HIS DAUGHTERS? …SONS? 5. ARE THERE ANY INDIVIDUALS WHOSE GENOTYPE CANNOT BE DETERMINED USING THIS PEDIGREE? Think about it! Think

59 E. Pedigrees 1. The genotypes and phenotypes of individuals can be deduced in pedigree charts a. unshaded square- normal male b. unshaded circle- normal female c. shaded square- affected male d. shaded circle- affected female_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click Think

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62 Society for Developmental Biology http://www.sdbonline.org/fly/aimain/images.htm accessed 30.04.08 A. Biotechnology A. Biotechnology D. Engineering Bacteria D. Engineering Bacteria E. Cloning E. Cloning C. Human Genome Project C. Human Genome Project B. DNA Profiling B. DNA Profiling

63 A. Biotechnology 1. The use of organisms to perform useful tasks is called biotechnology a. PCR b. gel electrophoresis_ Science Blogs http://scienceblogs.com/omnibrain/2007/10/guys_win_nobel_prize_for_makin.php accessed 30.04.08

64 A. Biotechnology 1. The use of organisms to perform useful tasks is called biotechnology a. PCR b. gel electrophoresis_ Science Blogs http://scienceblogs.com/omnibrain/2007/10/guys_win_nobel_prize_for_makin.php accessed 30.04.08 GE Healthcare http://www.mchem.btinternet.co.uk/SciImage/gel_blot_storm_storage_phosphor.htm accessed 30.04.08 GE Healthcare http://www.mchem.btinternet.co.uk/SciImage/gel_blot_storm_storage_phosphor.htm accessed 30.04.08 Click

65 2. PCR (polymerase chain reaction)- copies and amplifies minute quantities of DNA a. spots of blood b. hair roots c. small semen stain_ author unknown address unknown accessed unknown

66 2. PCR (polymerase chain reaction)- copies and amplifies minute quantities of DNA a. spots of blood b. hair roots c. small semen stain_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown ClickPlay

67 3. In gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size a. gel electrophoresis of DNA is used in DNA profiling b. contamination can be problematic_ author unknown address unknown accessed unknown

68 US National Library of Medicine NIH http://www.nlm.nih.gov/visibleproofs/galleries/cases/jeffreys_image_2.html accessed 04.05.08 B. DNA Profiling 1. DNA profiling is a method of identifying individuals using the non-coding regions of DNA a. non-coding regions of DNA contain hypervariable regions b. these regions have repeating nucleotide sequences c. the number and length of the sequences differ between individuals d. the closer the relationship the greater the similarities_

69 2. Forensic scientists can use DNA profiling to compare samples found at the scene of a crime with that of suspects a. used like traditional fingerprinting to help police with investigations_ The University of British Columbia http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/ accessed 04.05.08 Play

70 The University of British Columbia http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/ accessed 04.05.08 3. Another use of DNA profiling is for resolving paternity disputes a. DNA profiles from child and suspected father can be compared_

71 Web The University of British Columbia http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/ accessed 04.05.08 3. Another use of DNA profiling is for resolving paternity disputes a. DNA profiles from child and suspected father can be compared_ A COMPARISON COULD BE MADE BETWEEN BLOOD GROUPS AND DNA PROFILES IN THEIR POTENTIAL FOR DETERMINING PATERNITY. THE DIFFICULTY IN ASSESSING THE CHANCE OF TWO INDIVIDUALS HAVING THE SAME PROFILE COULD BE DISCUSSED, AND ALSO THE SUCCESS OF DNA PROFILING IN SECURING CONVICTIONS IN SOME OF THE HIGH-PROFILE LEGAL CASES OF RECENT YEARS. Theory of Knowledge TOK

72 C. Human Genome Project 1. The Human Genome Project is an international cooperative venture established to sequence the complete human genome 2. The outcomes of this analysis could include: a. knowledge of the number of human genes b. the location of specific genes c. discovery of proteins and their functions d. evolutionary relationships_ Affymetrix http://www.affymetrix.com/corporate/media/genechip_essentials/genotyping/Genotyping_DNA.affx accessed 24-04-07

73 Science Daily http://www.sciencedaily.com/releases/2007/09/070920145356.htm accessed 30.04.08 3. Potentially advantageous medicinal outcomes include: a. an understanding of many genetic diseases b. the development of genome libraries c. production of gene probes to detect sufferers and carriers of genetic diseases (eg Duchenne muscular dystrophy) d. production of pharmaceuticals based on DNA sequences_

74 3. Potentially advantageous medicinal outcomes include: a. an understanding of many genetic diseases b. the development of genome libraries c. production of gene probes to detect sufferers and carriers of genetic diseases (eg Duchenne muscular dystrophy) d. production of pharmaceuticals based on DNA sequences_ Science Daily http://www.sciencedaily.com/releases/2007/09/070920145356.htm accessed 30.04.08 THE HUMAN GENOME PROJECT WAS AN INTERNATIONAL ENDEAVOUR, WITH LABORATORIES THROUGHOUT THE WORLD COLLABORATING. HOWEVER, THERE WERE ALSO EFFORTS IN SOME PARTS OF THE WORLD TO GAIN COMMERCIAL BENEFITS FROM THE OUTCOMES OF THE PROJECT. THE DATA FROM THE HUMAN GENOME PROJECT CAN BE VIEWED IN DIFFERENT WAYS: IT COULD BE SEEN AS A COMPLETE ACCOUNT OF WHAT MAKES UP A HUMAN, IF ONE TAKES A REDUCTIONIST VIEW OF LIFE, OR, ALTERNATIVELY, AS MERELY THE CHEMICAL INSTRUCTIONS THAT HAVE ALLOWED A HUGE RANGE OF MORE SIGNIFICANT HUMAN CHARACTERISTICS TO DEVELOP. THIS COULD LEAD TO A DISCUSSION ABOUT THE ESSENTIAL NATURE OF HUMANITY. THE HUMAN GENOME PROJECT WAS AN INTERNATIONAL ENDEAVOUR, WITH LABORATORIES THROUGHOUT THE WORLD COLLABORATING. HOWEVER, THERE WERE ALSO EFFORTS IN SOME PARTS OF THE WORLD TO GAIN COMMERCIAL BENEFITS FROM THE OUTCOMES OF THE PROJECT. THE DATA FROM THE HUMAN GENOME PROJECT CAN BE VIEWED IN DIFFERENT WAYS: IT COULD BE SEEN AS A COMPLETE ACCOUNT OF WHAT MAKES UP A HUMAN, IF ONE TAKES A REDUCTIONIST VIEW OF LIFE, OR, ALTERNATIVELY, AS MERELY THE CHEMICAL INSTRUCTIONS THAT HAVE ALLOWED A HUGE RANGE OF MORE SIGNIFICANT HUMAN CHARACTERISTICS TO DEVELOP. THIS COULD LEAD TO A DISCUSSION ABOUT THE ESSENTIAL NATURE OF HUMANITY. Theory of Knowledge TOK

75 D. Engineering Bacteria 1. When genes are transferred between species, the amino acid sequence of polypeptides translated from them is unchanged because the genetic code is universal 2. The technique of gene technology typically involves the use of E. coli 3. Most of its DNA is in one circular chromosome, but it also has plasmids (smaller circles of DNA)_ Play author unknown address unknown accessed unknown

76 4. These plasmids can be removed and cleaved by restriction enzymes at target sequences a. restriction enzymes (endonuclease) “cut” 5. DNA fragments from another organism can also be cleaved by the same restriction enzyme and these pieces can be added to the open plasmid and spliced together by ligase a. DNA ligase “pastes”_ Play author unknown address unknown accessed unknown

77 6. The recombinant plasmids formed can be inserted into new host cells and cloned (copied) a. human genes can be “cut and pasted” into the plasmid b. host cells include bacteria, yeast, or other cell 7. Clone- a group of genetically identical organisms or a group of cells derived from a single parent cell_ Play author unknown address unknown accessed unknown

78 E. Cloning 1. Plants and animals are currently being genetically modified for: a. salt tolerance in tomato plants b. synthesis of beta- carotene (vitamin A precursor) in rice c. herbicide resistance in crop plants d. factor IX (human blood clotting) in sheep milk_ Play SCIENCE NEWS for KIDS http://www.sciencenewsforkids.org/articles/20040128/Feature1.asp accessed 04.05.08

79 2. There are potential benefits and possible harmful effects of genetic modification_ PHYSORG.com http://www.physorg.com/news116686493.html accessed 04.05.08

80 2. There are potential benefits and possible harmful effects of genetic modification_ PHYSORG.com http://www.physorg.com/news116686493.html accessed 04.05.08 WordPress.com http://hplusbiopolitics.wordpress.com/feed/ accessed 04.05.08 WordPress.com http://hplusbiopolitics.wordpress.com/feed/ accessed 04.05.08

81 2. There are potential benefits and possible harmful effects of genetic modification_ PHYSORG.com http://www.physorg.com/news116686493.html accessed 04.05.08 WordPress.com http://hplusbiopolitics.wordpress.com/feed/ accessed 04.05.08 WordPress.com http://hplusbiopolitics.wordpress.com/feed/ accessed 04.05.08 Click THIS IS AN OPPORTUNITY TO DISCUSS HOW WE CAN ASSESS WHETHER RISKS ARE GREAT ENOUGH TO JUSTIFY BANNING TECHNIQUES AND HOW THE SCIENTIFIC COMMUNITY CAN INFORM COMMUNITIES GENERALLY ABOUT POTENTIAL RISKS. INFORMED DECISIONS NEED TO BE MADE BUT IRRATIONAL FEARS SHOULD NOT BE PROPAGATED. CONSIDERATION COULD BE GIVEN TO THE PARADOX THAT CAREFUL RESEARCH IS NEEDED TO ASSESS THE RISKS, BUT PERFORMING THIS RESEARCH IN ITSELF COULD BE RISKY. DO PROTESTERS WHO DESTROY TRIALS OF GM CROPS MAKE THE WORLD SAFER. Theory of Knowledge TOK

82 3. Cloning using differentiated animal cells, Dolly the sheep a. cells taken from udder of an adult donor and cultured in laboratory for 6 days b. unfertilized egg taken form another sheep (nucleus removed form the egg) c. egg without nucleus fused with donor cell using a spark of electricity_ BBC http://www.bbc.co.uk/schools/gcsebitesize/science/21c/genes/genetherapycloningandstemcellsrev4.shtml accessed 08.05.08 Advanced Biology, Kent p. 409

83 3. Cloning using differentiated animal cells, Dolly the sheep a. cells taken from udder of an adult donor and cultured in laboratory for 6 days b. unfertilized egg taken form another sheep (nucleus removed form the egg) c. egg without nucleus fused with donor cell using a spark of electricity_ BBC http://www.bbc.co.uk/schools/gcsebitesize/science/21c/genes/genetherapycloningandstemcellsrev4.shtml accessed 08.05.08 BBC http://news.bbc.co.uk/1/hi/sci/tech/1809546.stm accessed 08.05.08 BBC http://news.bbc.co.uk/1/hi/sci/tech/1809546.stm accessed 08.05.08 Click

84 Advanced Biology, Kent p. 409 d. embryo resulting from fusion of udder cell and egg transferred to womb of a third sheep which will act as a surrogate mother e. surrogate mother gives birth to lamb “Dolly” which is genetically identical with the sheep that donated the utter cell (the donor)_ BBC http://www.bbc.co.uk/schools/gcsebitesize/science/21c/genes/genetherapycloningandstemcellsrev4.shtml accessed 08.05.08 Play

85 4. Reproductive cloning is a form of asexual reproduction a. the offspring’s genes come from the body cell of a single individual_ Association of Reproductive Health Professionals http://www.arhp.org/patienteducation/onlinebrochures/cloning/index.cfm?ID=282 accessed 08.05.08

86 5. Therapeutic cloning is the creation of an embryo to supply embryonic stem cells for medical use a. these cells have a the ability to differentiate into a variety of types of cells b. they can be cultures on petri dishes and potentially used to generate tissues and organs 6. Therapeutic cloning in humans poses ethical issues_ Association of Reproductive Health Professionals http://www.arhp.org/patienteducation/onlinebrochures/cloning/index.cfm?ID=282 accessed 08.05.08

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