Term
| What defines the "environment" for a developing embryo/fetus? |
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Definition
| Everything outside his/her own skin including the mother's body |
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Term
| What is the definition of teratology? |
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Definition
| The study of the auses, mechanisms, and manifestations of developmental defects of a structural and/or functional nature |
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Term
| What is the primary etiology behind the development of birth defects? |
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Definition
| 50-60% unknown, 20-25% multifactorial in nature |
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Term
| An abnormal number of chromosomes other than an exact multiple of the haploid number is known as what? |
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Definition
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Term
| An abnormal number of chromosomes that is an exact multiple of the haploid number is known as what? |
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Definition
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Term
| What is the most common trisomies of autosomes? |
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Definition
| Trisomy 21 (Down syndrome), Trisomy 18, Trisomy 13 |
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Term
| Turner syndrome (45,X) is an example of what type of numerical chromosomal abnormality? |
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Definition
| Monosomy of sex chromosomes |
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Term
| What are the symptoms of Down Syndrome? |
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Definition
| Growth retardation, varying mental retardation, upward slanting eyes with epicanthal folds, single palmar crease (simian crease) cardiac defects, hypotonia, altantoaxial instability (15%) |
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Term
| Why does the incidence of down syndrome increase dramatically with maternal age? |
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Definition
| Increased incidence of meiotic nondisjunction |
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Term
| What is the karotype of Klinefelter syndrome? |
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Definition
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Term
| What are the symptoms of Klinefelter syndrome? |
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Definition
| Tall stature, broad hips, testicular atrophy with hyalinized seminiferous tubules, gynecomastia, possible mental retardation |
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Term
| 40% of Klinefelter syndrome patients have gynecomastia, giving them an increased chance at developing what? |
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Definition
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Term
| What is the most common type of polyploidy? |
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Definition
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Term
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Definition
| Loss of part of a chromosome |
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Term
| What is the definition of translocation |
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Definition
| Transfer of a piece of one chromosome to an nonhomologous chromosome |
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Term
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Definition
| Incorporation into a chromosome of a duplicated segment |
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Term
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Definition
| The reversal of a segment of chromosome, usually following a double break |
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Term
| What is the definition of isochrosomes? |
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Definition
| The transverse trather than longitudinal division of the centromere joining two chromatids |
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Term
| What causes cri du chat syndrome? |
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Definition
| Partial deletion from chromosome 5 |
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Term
| What are the symptoms of cru du chat syndrome? |
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Definition
| Catlike cry, microcephaly, mental retardation, congenital heart disease |
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Term
| When is it possible for translocation to not be detrimental to development? |
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Definition
| If exchange is reciprocal and breaks do not occur |
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Term
| What is the most common cause of duplications? |
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Definition
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Term
| Which structural chromosomal defect usually does not result in an abnormal phenotype? |
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Definition
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Term
| 15-20% of women with what disease carry isochromosomes? |
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Definition
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Term
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Definition
| Mitotic nondisjunction of chromosomes |
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Term
| What are some environmental agents that cause developmental anomalies? |
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Definition
| Drugs, environmental chemicals, ionizing radiation, mechanical forces, infectious agents |
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Term
| What are some drugs that cause developmental defects? |
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Definition
| Thalidomide (sleeping pill), alcohol, aminopterin, retinoic acid (vit A), phenytoin |
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Term
| What traits are symptomatic of fetal alcohol syndrome? |
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Definition
| Microcephaly, maxillary hypoplasia, short palpebral fissures, joint abnormalities, cardiovascular defects |
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Term
| What kind of defects are caused by aminopterin? |
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Definition
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Term
| What causes fetal hydantoin syndrome? |
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Definition
| The anticonvulsant, phenytoin |
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Term
| What causes fetal Minamata disease? |
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Definition
| The environmental chemical methylmercury |
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Term
| What kind of mechanical factors can induce developmental defects? |
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Definition
| Oligohydramnios (too little amniotic fluid), uterine malformations, fetal growth restraint (multiple fetuses or uterine tumors), amniotic bands |
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Term
| What kinds of infectious agents can cause developmental anomalies? |
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Definition
| Toxoplasma gondii (intracellular parasite), Rubella virus (German measles, cytomegalovirus |
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Term
| What is the most common viral infection of the human fetus? |
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Definition
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Term
| What can cause a Toxoplasma gondii infection? |
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Definition
| Eating raw or poorly cooked pork or lamb, close contact with infected cats, may result in hydrocephalus |
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Term
| What kind of infection can cause cataracts and possibly glaucoma? |
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Definition
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Term
| Cytomegalovirus may cause what kind of defect of infection is later in gestation? |
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Definition
| Microphthalmia (eye that is toos mall) |
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Term
| The susceptibility of developing organisms to adverse environmental influences depends on what? |
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Definition
| The genotype of the conceptus and how it interacts with the environment (eg. thalidomide was tested for safety in rodents, but they are resistant to its teratogenic effects) |
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Term
| Vulnerability to teratogenesis depends on what? |
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Definition
| Developmental stage at the time of exposure |
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Term
| The results of abnormal development are what? |
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Definition
| Death, malformation, growth retardation, functional deficit, and transplacental carcinogenesis |
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