SCIENCE 9 UNIT 1 MODULE 2 [Autosaved].pptx

SCIENCE 9 UNIT 1 MODULE 2

1. LESSON 9

2. GENETICS

3. GENETICS IS THE SCIENTIFIC STUDY OF GENES AND HEREDITY—OF HOW CERTAIN QUALITIES OR TRAITS ARE PASSED FROM PARENTS TO OFFSPRING AS A RESULT OF CHANGES IN DNA SEQUENCE.

4. HEREDITY :INHERITANCE AND VARIATION

5. REVIEW TIME!

6. HUMANS HAVE 22 PAIRS OF NUMBERED CHROMOSOMES (AUTOSOMES) AND ONE PAIR OF SEX CHROMOSOMES (XX OR XY), FOR A TOTAL OF 46.

7. VOCABULARY

8. GENES-GENES ARE PASSED FROM PARENTS TO OFFSPRING AND CONTAIN THE INFORMATION NEEDED TO SPECIFY PHYSICAL AND BIOLOGICAL TRAITS ALLELE- A DIFFERENT FORM OF GENE THAT CONTROLS A CERTAIN TRAIT .

9. A GENE IS A PORTION OF DNA THAT DETERMINES A CERTAIN TRAIT. AN ALLELE IS A SPECIFIC FORM OF A GENE. GENES ARE RESPONSIBLE FOR THE EXPRESSION OF TRAITS . ALLELES ARE RESPONSIBLE FOR THE VARIATIONS IN WHICH A GIVEN TRAIT CAN BE EXPRESSED.

10. DOMINANT ALLELE-A DOMINANT ALLELE IS A VARIATION OF A GENE THAT WILL PRODUCE A CERTAIN PHENOTYPE, EVEN IN THE PRESENCE OF OTHER ALLELES.  RECESSIVE ALLELE-A RECESSIVE ALLELE DOES NOT PRODUCE A TRAIT AT ALL WHEN ONLY ONE COPY IS PRESENT. 

11. GENOTYPE- GENOTYPE CAN ALSO BE USED TO REFER TO THE ALLELES OR VARIANTS AN INDIVIDUAL CARRIES IN A PARTICULAR GENE OR GENETIC LOCATION. PHENOTYPE- PHENOTYPE REFERS TO AN INDIVIDUAL'S OBSERVABLE TRAITS, SUCH AS HEIGHT, EYE COLOR AND BLOOD TYPE. PUNNET SQUARE- THE PUNNETT SQUARE IS A SQUARE DIAGRAM THAT IS USED TO PREDICT THE GENOTYPES OF A PARTICULAR CROSS OR BREEDING EXPERIMENT.

12. PHENOTYPIC RATIO- A QUANTITATIVE RELATION BETWEEN PHENOTYPES SHOWING THE NUMBER OF TIMES THE FREQUENCY OF ONE PHENOTYPE CORRELATES WITH ANOTHER. GENOTYPIC RATIO-IT REPRESENTS THE PATTERN OF OFFSPRING DISTRIBUTION ACCORDING TO GENOTYPE, WHICH IS THE GENETIC CONSTITUTION DETERMINING THE PHENOTYPE OF AN ORGANISM.

13. WHAT IS THIS LESSON ABOUT? READ THE INTRO ON PAGE 28.

14. LESSON 10

15. MENDELLIAN PATTERN OF INHERITANCE VS. NON-MENDELLIAN PATTERN OF INHERITANCE

16. WHO IS THE FATHER OF GENETICS?

17. ARRANGE THE LETTERS TO GUESS WHO THE FATHER OF GENETICS IS RGOREG LMNDEEL

18. GREGOR MENDEL

19. WHO ARE THEY?

20. THEODOR BOVERI THEODOR HEINRICH BOVERI WAS A GERMAN ZOOLOGIST, COMPARATIVE ANATOMIST AND CO-FOUNDER OF MODERN CYTOLOGY. WALTER SUTTON WALTER STANBOROUGH SUTTON WAS AN AMERICAN GENETICIST AND BIOLOGIST WHOSE MOST SIGNIFICANT CONTRIBUTION TO PRESENT-DAY BIOLOGY WAS HIS THEORY THAT THE MENDELIAN LAWS OF INHERITANCE COULD BE APPLIED TO CHROMOSOMES AT THE CELLULAR LEVEL OF LIVING ORGANISMS.

21. GREGOR MENDEL FORM THE BASE FOR THE UNDERSTANDING OF HEREDITY AND VARIATION.ALTHOUGH MENDEL’S WORK FAILED TO DISCUSS THOUGHROUGHLY THE FACTORS OR GENES HE MENTIONED IN HIS LAWS OF INHERITANCE , HIS FINDINGS PROMPTED OTHER SCIENTISTS TO PROVE FURTHER INTO THE MYSTERY OF HEREDITY. SEVERAL RESEARCHES WERE CONDUCTED AFTER THE REDISCOVERY OF MENDEL’S WORK.

22. WALTER SUTTON AND THEODORE BOVERI BECAME POPULAR BECAUSE THEY FOUND THE BEST EVIDENCE THAT AN INHERITED TRAIT IS DETERMINED BY CHROMOSOMES. CHROMOSOME THEORY OF INHERITANCE EXPLAINED THAT GENES ARE IN THE CHROMOSOMES.

23. MENDELLIAN LAWS OF INHERITANCE HAVE IMPORTANT EXCEPTIONS TO THEM. FOR EXAMPLE , NOT ALL GENES SHOW SIMPLE PATTERNS OF DOMINANT AND RECESSIVE ALLELES.

24. ACTIVITY TIME! TH ETEACHER WILL DIVIDE YOU INTO 2 GROUPS AND ONE GROUP WILL EXPLAIN MENDELLIAN THEORY OF INHERITANCE WHILE THE OTHER WILL EXPLAIN THE NON MENDELLIAN PATTERN OF INHERITANCE NOTE:TAKE PICS OF THE INFORMATION THAT YOU ARE GOING TO REPORT

25. MENDELIAN PATTERN OF INHERITANCE MENDELIAN INHERITANCE REFERS TO AN INHERITANCE PATTERN THAT FOLLOWS THE LAWS OF SEGREGATION INDEPENDENT ASSORTMENT AND LAW OF DOMINANCE IN WHICH A GENE INHERITED FROM EITHER PARENT SEGREGATES INTO GAMETES AT AN EQUAL FREQUENCY.

26. NON-MENDELIAN PATTERNS OF INHERETANCE

27. NON-MENDELIAN INHERITANCE REFERS TO THE INHERITANCE OF TRAITS THAT HAVE A MORE COMPLEX GENETIC BASIS THAN ONE GENE WITH TWO ALLELES AND COMPLETE DOMINANCE .

28. QUIZ! MAKE A PUNETTE SQUARE USING THESE ALLELES AND IDENTIFY IF ITS MENDELIAN AND NON-MENDELLIAN PATTERN OF INHERITANCE. 1.SS-RED FISH ss - YELLOW FISH Ss -RED FISH 2.Yw-BLUE FLOWER Yz -YELLOW FLOWER YwYz -GREEN FLOWER

29. LESSON 11

30. MOTIVATION PART PUT A PICTURE THAT PEAKS THE STUDENTS INTEREST

31. CMOPINLEET MNIDONCEA

32. INCOMPLETE DOMINANCE

33. IN INCOMPLETE DOMINANCE, A HETEROZYGOTE (BABY) SHOWS A PHENOTYPE THAT IS INTERMEDIATE BETWEEN TWO HOMOZYGOUS (PARENT) PHENOTYPES.NEITHER ALLELE IS DOMINANT OVER THE OTHER

34. PICTURE HERE

35. IN INCOMPLETE DOMINANCE , IT IS ONLY THE PHENOTYPE THAT IS INTERMEDIATE . THE RED AND WHITE ALLELES REMANIN SEPARATE AND DISTINC .HALF THE GAMETES OF THE PINK FOUR O’CLOCK CARRY THE ALLELE FOR RED AND HALF CARRY THE ALLELE FOR WHITE .THEREFORE, THE GENOTYPIC RATIO ALSO BECOMES THE PHENOTYPIC RATIO

36. GIVE ANOTHER EXAMPLE USING PUNNETE SQUARE

37. GIVE AN EXAMPLE USING A PUNNETE SQUARE

38. LET THEM DO THE ACTIVITY ON PAGE 31.

39. QUIZ!

40. LESSON 12

41. MOTIVATION PART PUT A PICTURE THAT PEAKS THE STUDENTS INTEREST

42. IMCOODACNEN

43. CODOMINANCE

44. ANOTHER PATTERN OF INHERITANCE IS CODOMINANCE. THIS RESULTS WHEN ONE ALLELE IN NOT DOMINANT OVER THE OTHER .THE RESULTING HETEROZYGOTES EXHIBIT THE TRAITS OF BOTH PARENTS. ONE EXAMPLE OF CODOMINANCE IS MN BLOOD TYPING IN HUMANS .

45. ON THE SURFACE OF OUR RED BLOOD CELLS ARE PROTEINS BOUND TO SUGAR MOLECULES, FORMING COMPLEXES CALLED ANTIGENS(induces an immune response in the body, especially the production of antibodies.) . ONE GROUP OF ANTIGENS ARE CONTROLLED BY A PAIR ALLELES, LM AND LN . THE PAIRING OF THESE ALLELES WILL DETERMINE THE BLOOD TYPE OF AN INDIVIDUAL AND THERE ARE THREE:M, MN , AND N.

46. TABLE 1 SUMMARIZES THE GENOTYPES AND PHENOTYPES OF THE MN BLOOD TYPING IN HUMANS. BLOOD TYPES GENOTYPE M LMLM MN LMLN N LNLN NOTE THAT IN THE HETEROZYGOTE CONDITION, BOTH LM AND LN ALLELES ARE EXPRESSED SUCH THAT THE RED BLOOD CELLS WILL HAVE THE M AND N ANTIGENS . JUST LIKE IN INCOMPLETE DOMINANCE , THE GENOTYPIC RATIO IN CODOMINANCE ALSO BECOMES THE PHENOTYPIC RATIO.

47. GIVE ANOTHER EXAMPLE USING PUNNETE SQUARE ANOTHER GOOD EXAMPLE OF CODOMINANCE IS ROAN FUR IN CATTLE. CATTLE CAN BE RED *RR-ALL RED HAIRS, WHITE *WW-ALL WHITE HAIRS, OR ROAN *RW-RED AND WHITE HAIRS TOGETHER.

48. LET THEM DO THE ACTIVITY ON PAGE 33 .

49. QUIZ!

50. LESSON 13

51. MOTIVATION PART PUT A PICTURE THAT PEAKS THE STUDENTS INTEREST

52. ULMTPILEU SLLEALEL

53. MULTIPLE ALLELES

54. SOMETIMES,EVEN IF ONLY TWO ALLELES CONTROL A TRAIT, THERE MAY ACTUALLY BE MORE THAN TWO TYPES OF ALLELES AVAILABLE. THIS WILL ALSO LEAD TO MORE THAN TWO PHENOTYPES EXPRESSED.

55. ANOTHER BLOOD GROUP SYSTEM IN HUMANS , THE ABO SYSTEM , IS AN EXAMPLE OF A CHARACTER GOVERNED BY MULTIPLE ALLELES .THREE ALLELES ARE RESPONSIBLE FOR THIS BLOOD SYSTEM A, B, AND i . THE ABO BLOOD TYPE IS DETERMINED BY THE PRESENCE OR ABSENCE OF TWO ANTIGENS , A AND B. ALLELE i DOES NOT CODE FOR AN ANTIGEN. THERE ARE FOUR POSSIBLE BLOOD TYPES AS SHOWN IN TABLE 2.

56. TABLE 2: HUMAN ABO BLOOD TYPES AND THEIR PHENOTYPES BLOOD TYPES GENOTYPES A AA, Ai B BB, Bi AB AB O ii THE A AND B ALLELES ARE DOMINANT OVER THE I ALLELE , WHICH IS ALWAYS RECESSIVE . HOWEVER , WHEN THE A AND B ALLELES ARE INHERITED TOGETHER, BOTH ALLELES ARE EXPRESSED EQUALLY. THIS ALSO MAKES A ND B CODOMINANTD OF EACH OTHER.

57. LET THEM DO THE ACTIVITY ON PAGE 34.

58. QUIZ!

59. LESSON 14

60. MOTIVATION PART PUT A PICTURE THAT PEAKS THE STUDENTS INTEREST

61. SEX CHROMOSOMES AND SEX DETERMINATION

62. GAMETES ARE UNFERTILIZED REPRODUCTIVE CELLS .  ZYGOTE IS A FERTILISED EGG

63. HUMANS HAVE 46 CHROMOSOMES IN EACH CELL. OBSERVATION OF THE HUMAN BODY CELLS SHOWS 23 PAIRS OF CHROMOSOMES FROM BOTH MALES AND FEMALES.TWENTY-TWO PAIRS ARE SOMATIC CHROMOSOMES. THE 23 RD PAIR CONSISTS OF SEX CHROMOSOMES . HUMAN MALES AND SOME OTHER MALE ORGANISMS, SUCH AS OTHER MAMMALS AND FRUIT FLIES , HAVE NON-IDENTICAL SEX CHROMOSOMES XY , FEMALES HAVE IDENTICAL XX SEX CHROMOSOMES.

64. HOW IS SEX DETERMINED AND INHERETED? ALL EGG CELLS RECEIVE AN X CHROMOSOME, WHILE THE SPERM CELLS RECEIVE X CHROMOSOMES AND THE OTHER HALF RECEIVE Y CHROMOSOMES.

65. X X X Y FEMALE XX MALE XY SEX CHROMOSOMES MEIOSIS GAMETES

66. NOTE THAT THERE IS A 50 PERCENT CHANCE OF HAVING A MALE OR FEMALE OFFSPRING .

67. FEMALE XX MALE XY X X X Y XX FEMALE XX FEMALE XY MALE PARENT GAMETES FERTILIZATION ZYGOTE XY MALE

68. LET THEM DO THE ACTIVITY ON PAGE 37.

69. QUIZ

70. SEX-LINKED GENES

71. MOTIVATION PART PUT A PICTURE THAT PEAKS THE STUDENTS INTEREST

72. GENES LOCATED ON THE X CHROMOSOSMES ARE CALLED X-LINKED GENES . GENES ON THE Y CHROMOSOMES ARE CALLED Y-LINKED GENES. AN EXAMPLE OF AN X-LINKED TRAIT IN HUMANS IS HEMOPHILIA. A PERSON SUFFERING FROM HEMOPHILIA COULD DIE FROM LOSS OF BLOOD EVEN FROM A SMALL WOUND BECAUSE THE BLOOD EITHER CLOTS VERY SLOWLY OR NOT CLOT AT ALL. .

73. ANOTHER EXAMPLE OF AN X-LINKED TRAIT IS COLOR BLINDNESS.TO ILLUSTRATE THE INHERITANCE OF AN X-LINKED TRAIT, WE WILL USE COLOR BLINDNESS IN OUR DISCUSSION .LET US STUDY TABLE 3. THE X CHROMOSOME WITH GENE FOR COLOR BLINDNESS IS REPRESENTED AS Xc , WHILE ONE IS REPRESENTED WITH X

74. GENOTYPE PHENOTYPE 1.XX NORMAL FEMALE 2.XXc NORMAL FEMALE, CARRIER OF GENE 3.XcXc COLOR-BLIND FEMALE 4.XY NORMAL MALE 5.XcY COLOR-BLIND MALE

75. CAN YOU IDENTIFY THE GENOTYPE OF THE FEMALE WHO IS COLOR BLIND? NOTICE THAT FOR A FEMALE TO BECOME COLOR-BLIND, SHE MUST BE HOMOZYGOUS XcXc FOR THE COLOR-BLIND GENES. THE TRAIT IS, THEREFORE, RECESSIVE IN FEMALES. IF A FEMALE HAS ONLY ONE X CHROMOSOME WITH THE ALLELE FOR COLOR BLINDNESS , SHE BECOMES NORMAL BUT CAN PASS ON THE TRAIT TO HER OFFSPRING .SHE IS THEREFORE A CARRIER OF THE TRAIT . SINCE MALES HAVE ALWAYS BE EXPRESSED BECAUSE IT DOES NOT HAVE AN ALLELE TO HIDE OR PREVENT ITS EXPRESSION.THUS, MALE WILL BE COLOR-BLIND . THIS IS THE REASON WHY COLOR BLINDNESS IS MORE COMMON IN MALES THAN IN FEMALES.

76. FIGURE 5 IS AN EXAMPLE OF A Y-LINKED TRAIT, HYPERTRICHOSIS PINNAE AURIS, A GENETIC DISORDER IN HUMANS THAT CAUSES HAIRY EARS. SINCE THE TRAIT IS FOUND IN THE Y CHROMOSOME, THEN ONLY MALES CAN HAVE THE TRAIT . A FATHER WHO HAS THE CONDITION WILL PASS IT ON TO ALL HIS SONS, AND THEY, IN TURN, WILL PASS IT ON THEIR OWN SONS.

77. LET THE STUDENTS DO THE ACIVITY ON PAGE 39.

78. LESSON 16

79. SEX-LIMITED TRAITS

80. SEX-LIMITED TRAITS ARE GENERALLY AUTOSOMAL, WHICH MEANS THAT THEY ARE NOT FOUND ON THE X OR Y CHROMOSOMES (IT AFFECTS BOTH GENDERS). THE GENES FOR THESE TRAITS BEHAVE EXACTLY THE SAME WAY THAT ANY AUTOSOMAL GENE BEHAVES. THE DIFFERENCE HERE COMES IN THE EXPRESSION OF THE GENES IN THE PHENOTYPE OF THE INDIVIDUAL. SEX-LIMITED TRAITS ARE EXPRESSED IN ONLY ONE GENDER. IN CATTLE, FOR , INSTANCE LACTATION IS EXPRESSED IN FEMALES BUT NEVER IN MALES.

81. BOTH MALE AND FEMALE CATTLE HOWEVER POSSESS A GENE PAIR FOR LACTATION. THE GENE FOR LACTATION *L IS DOMINANT OVER NON-LACTATING GENE l .TABLE 4 SHOWS THE GENOTYPES AND PHENOTYPES OF THE GENE FOR LACTATION. THESE GENES ARE CARRIED BY BOTH MALES AND FEMALES , BUT IS ONLY EXPRESSED IN FEMALES. HAVE YOU NOTICED THAT IN FEMALE CATTLE , IF AT LEAST ONE GENE PAIR IS FOR LACTATION *L , THE FEMALE PRODUCES MILK?IN MALE CATTLE , IT DOES NOT MATTER IF THEY POSSESS ONE OR TWO GENES FOR LACTATION. THEY NEVER PRODUCE MILK.

82. FEMALE GENOTYPES FEMALE PHENOTYPES XLXLL FEMALE LACTATING XlXL FEMALE LACTATING XlXl FEMALE NOT LACTATING MALE GENOTYPES MALE PHENOTYPES XLYL MALE NOT LACTATING XIYL MALE NOT LACTATING XIYl MALE NOT LACTATING

83. QUIZ

84. SEX-INFLUENCED TRAITS

85. SEX-INFLUENCED TRAITS ARE ALSO AUTOSOMAL , IT MEANS THAT THEIR GENES ARE NOT CARRIED ON TO THE SEX CHROMOSOMES. AGAIN, WHAT MAKES THESE TRAITS UNSUAL IS THE WAY THEY ARE EXPRESSED PHENOTYPICALLY. IN THIS CASE, THE DIFFERENCE IS IN THE WAYS THE TWO GENDERS EXPRESSED THE GENES.

86. ONE CLASSIC EXAMPLE OF A SEX-INFLUENCED TRAIT IS PATTERN BALDNESS IN HUMANS, THOUGH THE CONDITION IS NOT RESTRICTED TO MALES. THIS GENE HAS TWO ALLELES , BALD AND NON-BALD. THE BEHAVIORS OF THE PRODUCTS OF THESE GENES ARE HIGHLY INFLUENCED BY THE HORMONES IN THE INDIVIDUAL, PARTICULARLY IN THE HORMONE TESTOSTERONE .

87. ALL HUMANS HAVE TESTOSTRONE, BUT MALES HAVE MUCH HIGHER LEVELS OF THIS HORMONE THAN FEMALES DO.THE RESULT IS THAT , IN MALES, THE BALDNESS ALLELE BEHAVES LIKE A DOMINANT ALLELE , WHILE IN FEMALES IT BEHAVES LIKE A RECESSIVE ALLELE.

88. TABLE 5. EXPRESSION OF PATTERN BALDNESS IN HUMANS. MALE GENOTYPES MALE PHENOTYPES XBYB MALE BALD XBYb MALE BALD XbYb MALE NONBALD FEMALE GENOTYPES FEMALE PHENOTYPES XBXB FEMALE BALD XBXb FEMALE NONBALD XbXb FEMALE NONBALD

89. LET THE STUDENTS DO THE ACTIVITY ON PAGE 41

90. QUIZ

91. DNA: THE GENETIC MATERIAL

92. MOTIVATION PART

93. DNA MEANS *DEOXYRIBONUCLEIC ACID . THE WORK OF EARLIER SCIENTISTS GAVE WATSON AND CRICK A LOT OF INFORMATION ABOUT DNA. BY THE END OF 1940’S , SCIENTISTS HAD FOUND THAT DNA CONSISTS OF LONG STRANDS OF NUCLEOTIDES. EACH NUCLEOTIDE CONTAINS PENTOSE SUGAR CALLED DEOXYRIBOSE , A PHOSPHATE GROUP, AND ONE OF THE FOUR COMPOUNDS CALLED NITROGENOUS BASES .

94. A MOLECULE OF DEOXYRIBOSE JOINS WITH PHOSPHATE AND ANYONE OF THE FOUR BASES TO FORM A CHEMICAL COMPOUND CALLED A NUCLEOTIDE. A NUCLEOTIDE IS NAMED FOR THE BASE THAT JOINS WITH DEOXYRIBOSE. FOR EXAMPLE , IF THYMINE ATTACHES TO DEXYRIBOSE , THE MOLECULE IS CALLED THYMINE NUCLEOTIDE.

95. DNA IS COMPOSED OF CHAINS OF NUCLEOTIDES BUILT ON SUGAR AND PHOSPHATE BACKBONE AND WRAPPED AROUND EACH OTHER IN THE FORM OF A DOUBLE HELIX. THE BACKBONE SUPPORTS FOUR BASES:GUANINE, CYTOSINE, ADENINE, AND THYMINE. GUANINE AND CYTOSINE ARE COMPLEMENTARY , ALWAYS APPEARING OPPOSITE EACH OTHER ON THE HELIX, AS ARE ADENINE AND THYMINE. THIS IS CRITICAL IN THE REPRODUCTION OF THE GENETIC MATERIAL, AS IT ALLOWS A STRAND TO DIVIDE AND COPY ITSELF, SINCE IT ONLY NEEDS HALF OF THE MATERIAL IN THE HELIX TO DUPLICATE SUCCESSFULLY.

96. NUCLEOTIDE

97. PUT A PICTURE OF A DNA HERE

98. THE STRUCTURE OF THE DNA IS ACTUALLY IN A DOUBLE HELIX ARRANGEMENT AS SHOWN IN FIGURE 6. DOUBLE HELIX MEANS THAT LONG CHAINS OF NUCLEOTIDES ARE ARRANGED IN A SPIRAL LIKE TWISTED LADDER

99. FOUR TYPES OF DNA MOLECULE

100. LET THE STUDENTS DO THE ACTIVITY ON PAGE 43

101. QUIZ