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20 Cards in this Set
- Front
- Back
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3 diff methods of sex selecting
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1. pre-implantation methods
2. post-implantation methods 3. post-birth methods |
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pre implantation methods
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a. preconceptual (shettles method, sperm sorting)
b. post-conceptual: pre-implantation genetic diagnosis |
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post-implantation methods
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prenatal diagnosis (chorion biopsy/chorionic villus sampling, amniocentsis, baby gender mentor), selective abortion
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post birth methods
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infanticide
adoption |
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shettles method
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assumes x-bearing sperm swim slower, live longer (shallow penetration)
y-bearing sperm swim faster, don't live as long (deep penetration) |
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sex selecting
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assumes x/y bearing sperm differ in motility, size
*enrich either x or y bearing sperm |
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ericsson method/sperm spinning
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semen added on top of gradient of human serum albumin
*y sperm will reach bottom before x sperm too simple, doesn't work |
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MicroSort
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x bearing sperm has 3% more DNA- use fluorescent probe to separate x from y bearing
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PGD
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(99% effective)
embryo biopsy- remove single cell, see x and y chromosomes |
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chorionic villus sampling
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harvest cells from part of placenta (99% accuracy)
first trimester, 1% rate of miscarriage |
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ultrasound
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11-13 weeks in
less invasive |
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amniocentesis
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most common (15-20 weeks in)
extract small amt of amniotic fluid surrounding fetus |
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baby gender mentor
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supposedly access fetal DNA from mother's blood
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noninvasive fetal sex determination (using cell free fetal DNA)
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new method- detect free fetal DNA in maternal blood
-highly sensitive and specific |
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infanticide
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economic reasons- boys preferred
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sex ratio at birth
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number of male live births for every 100 female births
-hard to know accurately (home births, infanticide) -consistent across pops (105-107 for every 100) |
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factors influencing sex ratio at birth
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fam size
parental age parental job stress etc |
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population sex ratio
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figures taken from census data, total number of males for every 100 females in pop
1. sex ratio at birth 2. diff mortality rates 3. migration |
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son preference...why?
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earn higher wages
continue family line inheritance |
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high sex ratio
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discrimination- higher female mortality (abuse)
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