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16 Cards in this Set
- Front
- Back
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ZYGOTE |
THE NEW CELL FORMED BY THE PROCESS OF FERTILIZATION. |
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GENES |
THE BASIC UNITS OF GENETIC information. |
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GENOTYPE |
The underlying combinationcombination of genetic material present (but not outwardly visible.) In an organism. |
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PHENOTYPE |
AN OBSERVABLE TRAIT ; THE TRAIT THAT IS ACTUALLY SEEN. |
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MONOZYGOTIC (IDENTICAL) |
ARE TWINS WHO ARE GENETICALLY IDENTICAL Any differences in their future development vcan be attributed only to environmental factors, since genetically they are exactly you the same. |
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DIZYGOTIC(fraternal twins) |
Twins who are produced when two separate ova are fertilized by two separate sperm at roughly the same time. |
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DOMINANT TRAITS |
the one trait that is expressed when two competing traits are present |
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RECESSIVE TRAITS |
A trait within an organism that is present, but is not expressed. |
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how sex of a baby is determined? |
The 23rd pair consists of two matching, relatively large, X-shaped chromosomes,appropriately identified as XX. (In females)
In males , the members of the pair are dis- similar. One consists of an X shaped chromosome, but the other is shorter, smaller, Y-shaped chromosome. Identified as XY. |
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identify three stages of the prenatal period. |
1.GERMINAL(FERTILIZATION to 2 WEEKS.) 2.EMBRYONIC(2 weeks to 8 weeks.) 3.FETAL(8 weeks to BIRTH) |
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germinal stage |
the germinal stage is the first and shortest characterized by methodical cell division and the attachment of the organism to the wall of the uterus. |
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EMBRYONIC |
The embryo develops three layers,which ultimately form a different set of structures as development proceeds. 1.ECTODERM: Skin,hair,teeth,sense organs,brain,spinal cord. 2.Endoderm: Digestive system,liver,pancreas,respiratory system. 3.Mesoderm:Muscles,bones,blood,circulatory system at 8 weeks, the embryo is 1 inch long. |
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FETAL |
The fetal stage formally starts when the differentiation of the major organs has occurred.Now called a fetus,the individual grows rapidly as length increases20 times. At four months, the fetus weighs an average of 4 ounces; at 7 months,3 pounds;and at the time of birth the average child weighs just over 7 pounds. |
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TERATOGEN. |
Is an environmental agent such as a drug,chemical,virus,or there factor that produces a birth defect. |
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EXAMPLES OF TERATOGENS |
1.the brain is most susceptible 15 to 25 days after conception 2.The heart is most vulnerable 20 to 40 days following conception. Living on poverty increases the chances of exposure to teratogens.
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Know how fathers effect the prenatal environment. |
Smoking Use of alcohol illegal drugs A fathers exposure to environmental toxins in the workplace,such as lead or mercury,cmay cause the toxins to bind themselves to sperm and cause birth defects Fathers who are physically or emotionally abusive to their pregnant wives can damage their unborn children. |
