Lifespan Psychology. Chapter 3 Biology of Development. Outline. Infertility. Infertility/Reproductive technologies. Heredity/DNA/Genes

Transcription

1 Lifespan Psychology Chapte 3 Biology of Development 1 Outline Infetility/Repoductive technologies Pobabilities Fetility ypoblems and teatments Legal and ethical issues Adoption Heedity/DNA/Genes 2 Infetility pobabilities of fetilization - bith affects many Ameican couples 1 in 10 to about 1 in 6 (10-17%) women - most commonly blockage o abnomality of fallopian tubes men - low spem count o low spem motility 6 1

2 Medical technologies test tube baby (in vito fetilization) common pocedue now in use fo ove thee decades US fist in 1981, now 4 million wold wide, 58,000 yealy in US no guaantee of success, oveall about 29%/egg etieval 7 Othe medical options Fetility dugs stimulate matuation/elease of eggs stimulate "nomal" ovulation dugs can develop/maintain the uteine lining fetility dugs = inceased p(multiple biths) atificial insemination suogate mothes 8 Issues with epoductive technologies advantages and disadvantages? ethical issues? law owneship of embyos? ights/obligations of "othe paent?" vey expensive who pays? adoption tends 9 2

3 The human body contains about 100 tillion cells. Thee is a nucleus inside each human cell (except ed blood cells). Heedity & DNA Each nucleus contains 46 chomosomes, aanged in 23 pais. One chomosome of evey pai is fom each paent. The chomosomes ae filled with tightly coiled stands of DNA. Genes ae segments of DNA that contain instuctions to make poteins the building blocks of life. 13 Genes 20-25,000 diffeent genes same in evey cell in each peson no exact numbe yet all have complete set of genes few at wok in any one cell 14 Functions of genes diect "housekeeping" choes metabolic functions few hunded cay codes fo poteins only fo that type of cell Twins monozygotic dizygotic genetic elatedness of MZ and DZ twins? 15 3

4 Genetic Inheitance Gego Mendel ( ) discovey in the 1860's ignoed until "ediscoveed" aound 1900 Heedity tansmitted in discete units not via "blending" mom and dad's taits childen esemble thei paents attibuted to "blending of bloods" oigin of "bloodlines" & "in the blood" 16 Mendel's wok pea plants taits that came in pais of allelles simple pais of taits. tall vs. shot; puple vs. white flowes; winkled vs. smooth peas offsping always one o the othe 17 Coss beeding a shot and a tall plant, whee: both paents the same as thei paents 100% tall plants two of these tall offsping 75% tall and 25% shot plants (oughly) 18 4

5 Mendel concluded (coectly) each paent caies 2 units of heedity govening each tait sex cells only cay one unit of heedity each; spem and egg each contibute one unit to pai when combined in offsping, one may dominate the othe 19 In the pea plant "tall" genes dominate "shot" 1 tall and 1 shot gene = no blending the plant gows tall shot o second gene doesn't matte 20 Genetics continued Recessive genes can emege to take contol in subsequent geneations dominant - ecessive status of human chaacteistics Genotype and Phenotype Genotype: Set of genes a peson inheits Phenotype: Set of taits a peson actually displays 21 5

6 Pea plant thid geneation Remembe, both of the paents ae tall plants that wee the offsping of a tall and a shot plant that wee the same as thei paents. So they came fom paents that wee TT and tt t #2 Shot Paen Paent #2 Paent #1 T T t t Paent #1 T t T TT Tt t tt Shot 22 Risk of Selected Genetic Disodes Chomosomal Down Syndome 1/800 Klinefelte syndome (XXY) 1/800 men Fagile X syndome 1/1,200 male biths 1/2,000 female biths Tune syndome (XO) 1/3,000 women Dominant Gene Polydactyly Achondoplasia Huntington disease Recessive Gene Cystic fibosis Sickle-cell disease Tay-Sachs disease X Linked Hemophilia Multifactoial Congenital heat disease Neual tube defect Cleft lip/cleft palate 1/300-1/100 1/2,300 1/15,000-1/5,000 1/2,500 white pesons (isk of being a caie is 1/25) 1/625 Afican Ameicans (isk of being a caie is 1/10) 1/3,600 Easten Euopean Jews(isk of being a caie is 1/30-1/300) 1/2,500 male babies 1/ /1,000 1/1,000-1/5,000 Souces: ACOG (1990); Blatt (1988); Diamond (1989); Hageman (1996); Selekman (1993); Statfod (1994). 23 Inheitance of a Dominant Gene Disode Affected Paent (Has the Disode) D D Affected nomal Fathe D Affected nomal (50%) (50%) 24 6

7 Inheitance of a Recessive Gene Disode Caie Fathe D Caie Mothe D DD D D Affected 25 Inheitance of Hemophilia, a Sex- Linked Disode Fathe X Y Caie Mothe X X XX Daughte XX Caie Daughte ( ) XY Son XY Hemophilic Son 26 7