Genetics Flashcards
Law of segregation
Dominant and recessive traits passed from parent to offspring
Law of independent assortment
Traits passed independently of each other
Germinal mutations
Occur during egg or sperm formation
Somatic mutation
Mutation occurs after conception
Chromosomal mutation
Alteration in number of physical structure of a CS
Trisomy 21
1:800 births Cardiac defects, intentional malformation, vision abnormalities, hearing loss, respiratory infections, increased risk of Alzheimer’s
Klinefelter syndrome
XXYMost common primary hypergonadism
Turner syndrome
XO1:10,000Female appearance w short wide chest, neck skin folds, small breastsHypothyroidism, renal cardiac vision abnormalities, diabetes
Autosomal dominant
Equal male female distribution Vertical patternOnly one parent needs to be affected
Autosomal recessive
Horizontal patternEqual male female distribution Both parents carriers
X linked
Males affectedPassed from mother to son
Karyotyping
Culture blood amniotic fluid and skin cellsArrange into pairs by length
Fluorescent in situ hybridization
Identify where gene falls on chromosome with probes
Gregor Mendel
Father of genetics”Blending theory” cross breeding pea plants for single loci traits
Fertilization
Initiated meiotic division
Occurs in ampullary region of Fallopian tube
Pre-embryonic stage
Week 1
Forms morula the blastula
Ends w implantation
Embryonic stage
Day 8-week 8
Germ layers differentiate
Amniotic cavity forms
Fetal stage
Week 8- birth
Teratogenesis
Causing birth defects
Dose and stage dependent
Critical period between 3-16 weeks
Thalidomide
Limb abnormalities: amelia, meromelia, phocomelia Deafness Blindness Cleft palate Congenital heart disease
Diethylstibestrol
Used to prevent spontaneous abortion
Moms breast cancer
Daughters vaginal cancer, infertility
Vitamin a in pregnancy
Cleft lip and palate
Hydrocephalus
Cardiac deformities
Fetal alcohol syndrome disorder
Abnormal brain structure
Decreased impulse control and judgement
Abnormal info transfer
Memory and learning impairment
Cocaine and pregnancy
Spontaneous abortion
Placental abruption
Premature birth
iUGR