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62 Cards in this Set
- Front
- Back
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Longitudinal Research |
• In longitudinal research – same people are observed repeatedly over time, and changes in development are recorded • Typical time of study spans months or a few years • Longitudinal researchers must enlist future researchers to continue the study |
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Cross-Sectional Research |
• Cross-sectional research observes and compares subjects of different ages – a larger number of participants is needed for this type of study |
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Cohort effect |
– Group of people born at the same time will experience cultural and other events unique to age group |
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Cross-Sequential Research |
• Combines longitudinal and cross-sectional methods to overcome research drawbacks • Breaks up the full span of the ideal longitudinal study into convenient segments • Minimizes the number of years needed to complete a study • Uses time-lag comparisons |
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Ethical Considerations |
• Do not use methods that may cause physical or psychological harm • Inform participants of the purposes of the research and its methods • Participation must involve voluntary consent • Participants may withdraw from study at any time, for any reason • Participants are offered information about the results of the study • Identities of participants remains confidential • Research plans are to be presented to a committee of colleagues and gain approval before proceeding |
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Genetics |
- the field of biology that studies heredity – Fundamental in the transmission of physical traits – Also plays a role in psychological traits |
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Chromosomes |
– Rod-shaped structures composed of genes that are found within the nuclei of cells •. |
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Gene |
– The basic unit of heredity. Composed of DNA |
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Polygenic |
– Resulting from many genes |
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Deoxyribonucleic Acid (DNA) |
– Genetic material that takes the form of a double helix composed of phosphates, sugars and bases |
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Mitosis |
– Genetic code carried into new cells in our bodies DNA breaks apart; double helix duplicates • DNA forms two camps on either side of the cell, and then the cell divides |
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Meiosis |
• Sperm and ova are produced through meiosis or reduction division. • 46 chromosomes within the cell nucleus first line up into 23 pairs. • DNA ladders unzip, leaving unpaired halves of chromosome; when cell divides, one member of each pair goes to each newly formed cell. • Each new cell nucleus contains only 23 chromosomes, not 46. |
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Monozygotic (MZ) |
- Zygote divides into two cells that separate so that each develops into an individual with the same genetic makeup |
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Dizygotic (DZ) |
- Two ova are produced in the same month, each fertilized by a different sperm cell. |
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Traits determined by pairs of genes – each member of pairs of genes termed an |
allele |
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Dominant trait |
– trait that is expressed |
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Recessive trait |
– trait that is not expressed when genes have been paired with dominant genes |
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Homozygous |
– having two identical alleles |
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Heterozygous |
Heterozygous – having two different alleles |
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Incomplete dominance/codominances |
– when both alleles are shown |
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Carriers |
– people who bear one dominant gene and one recessive trait |
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Down syndrome |
– Caused by an extra chromosome of the 21st pair, resulting in 47 chromosomes • Characteristic features -rounded face -protruding tongue -broad, flat nose -sloping fold of skin over the inner corners of the eyes • Show deficits in cognitive development and motor developmen |
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1 male in 700-1,000 has XYY |
– leads to heightened male secondary sex characteristics – most individuals with disorder are infertile |
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1 male in 500 has Klinefelter syndrome (XXY) |
– leads to inadequate development of male primary and secondary sex characteristics |
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1 female in 2,500 has a single X resulting in Turner Syndrome |
– poorly developed ovaries, short, and infertile. |
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female in 1,000 has XXX sex chromosomal structure called Triple X syndrome |
– normal in appearance but tend to show lower-than-average language skills and poorer memory for recent events |
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Phenylketonuria (PKU) |
• Enzyme disorder transmitted by a recessive gene affecting 1 child in 8,000 • Cannot metabolize an amino acid called phenylalanine; builds up in body and impairs functioning of the central nervous system (CNS) • Results are mental retardation, psychological disorders, physical problems • No cure, but children can be placed on diets low in phenylalanine and develop normally |
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Sex-Linked Genetic Abnormalities |
• Genetic defects only carried on the X sex chromosome • Hemophilia – genetic disorder in which blood does not clot properly • Duchenne – muscular dystrophy; sex linked • Involve recessive genes • Females with two X sex chromosomes are less likely than males to show sex-linked disorder • Sons of female carriers are more likely to be afflicted |
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factors that contribute to development of traits |
Inheritance, nutrition, learning, exercise, accident, and illness |
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Phenotypes |
-Actual set of traits -Both genetic and environmental influences |
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Amniocentesis |
• Performed on mother 14-16 weeks after conception • Syringe withdraws fluid from the amniotic sac; contains cells sloughed off by fetus • Cells separated, grown in culture, and examined for genetic and chromosomal abnormalities • Routine for women over 35 to detect for Down syndrome; other chromosomal abnormalities increase dramatically as women approach 40 • Amniocentesis carries some risk of miscarriage. |
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Chorionic Villus Sampling |
• Carried out between 9th and 12th week of pregnancy • Syringe inserted through vagina into uterus to suck out threadlike projections (villi) from the outer membrane that covers the amniotic sac and fetus • Results available in days • CVS slightly greater risk than amniocentesis of miscarriage; both increase the risk of miscarriage |
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Ultrasound |
U • Sound waves that are too high in frequency to be heard by human ear obtain information about the fetus • Ultrasound waves are reflected by the fetus; computer uses the information to generate a picture of the fetus • Picture is termed a sonogram • Used to guide the syringe in amniocentesis and CVS by determining the position of the fetus • Used to track growth of fetus, detect multiple pregnancies, detect structural abnormalities |
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Blood Tests |
• Used to identify sickle-cell anemia, Tay-Sachs disease, and cystic fibrosis • Alpha-fetoprotein (AFP) used to detect neural tube defects such as spina bifida and chromosomal abnormalities • Neural tube defects cause elevation in the AFP level in the mother’s blood • Elevated AFP levels related to increased risk of fetal death |
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Prenatal Development • Normal gestation period |
280 days; from date of fertilization 266 days • |
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Prenatal Development Divided into three periods |
1. Germinal stage (Weeks 0 - 2) 2. Embryonic stage (Weeks 3 - 8) 3. Fetal stage (Weeks 9 - Birth) |
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The Germinal Stage |
• The period from conception to implantation • Conception refers to the union of an ovum and a sperm cell to form a zygote • Within 36 hours after conception, the zygote begins rapid division process |
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Implantation happens when ... |
fertilized egg attaches itself to the uterine wall -At this point, cells begin to specialize and separate into groups that will become different structures -These cells eventually become the fetus |
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embryonic disk |
Inner part of blastocyst has two distinct layers that form a thickened mass of cells called embryonic disk |
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The Embryonic Stage |
• Development follows cephalocaudal (head to tail) and proximodistal (near to far). • Growth of the head takes precedence over growth of the lower parts of the body. • Relatively early maturation of the brain and organs that lie near the spine • Cells begin to differentiate/become specialized: |
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Ectoderm |
-Outer layer of cells -Develops into nervous system, sensory organs, nails, hair, teeth, and outer layer of skin |
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Endoderm |
-Forms digestive and respiratory system, liver, and pancreas |
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Mesoderm |
-Develops into excretory, reproductive, and circulatory systems, muscles, the skeleton, and the inner layer of skin |
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The Fetal Stage |
• Lasts from beginning of third month until birth • Between 9th and 10th, week fetus responds to external stimulation • Major organ systems formed at end of first trimester • Second trimester consists of further maturation and gain in size • Weight advances from 1 ounce to 2 pounds and grows from about 3 to 14 inches |
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Maternal malnutrition effects |
-low birth weight -prematurity -retardation of brain development -cognitive deficiencies -behavioral problems -cardiovascular disease Fetal malnutrition can sometimes be overcome by a supportive, care-giving environment. • Supplementing diets of pregnant women shows positive effects on motor development of infants. • Maternal obesity linked with higher risk of stillbirth |
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Teratogens |
-Environmental agents can harm the embryo or fetus -Includes drugs taken by mother, lead, mercury |
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Pathogens |
-Disease-causing organisms -Bacteria and viruses |
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Critical periods refer to .... |
the times when organs are developing. • Particular teratogens at a particular time can be harmful to the fetus. |
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Rubella |
-Women affected by rubella (German measles) during first 20 weeks of pregnancy stand 20% chance of bearing children with birth defects such as deafness, mental retardation, heart disease, eye problems (including blindness) |
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Preeclampsia (or Toxemia) |
-Life-threatening; characterized by high blood pressure that may afflict women late in 2nd trimester or early in 3rd trimester |
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Rh incompatibility |
-Consists of antibodies produced by the mother and transmitted to a fetus or newborn infant that cause brain damage or death |
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Thalidomide |
-A sedative used for treatment of insomnia and nausea -Causes missing or stunted limbs during second month of pregnancy |
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High doses of vitamins A and D |
-Associated with central nervous system damage, small head size, and heart defects |
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Narcotics (heroine, methadone) |
easily pass placental membrane and cause fetuses to become addicted. -After birth, drug is substituted so serious withdrawal symptoms are minimized -Addicted newborns may have behavioral effects, motoric delays, language delays |
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Marijuana |
• Contributes to slower fetal growth, low birth weight • Babies of women who regularly used marijuana show increased tremors and startling, suggesting immature development of the nervous system. |
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Study by Goldschmidt et al. (2000) indicates prenatal exposure to marijuana can result in |
-increased hyperactivity -impulsivity -problems paying attention -increased delinquency and aggressive behavior |
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Cocaine |
• Cocaine use during pregnancy increases risk of stillbirth, low birth weight, and birth defects. • Infants are excitable, irritable, or lethargic; sleep is disturbed • Suggestions of delays in cognitive development even at 12 months of age • Prenatal exposure linked to lower receptive and expressive language abilities at older ages |
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Alcohol |
• Heavy alcohol consumption during pregnancy can result in fetal alcohol syndrome (FAS). |
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FAS babies |
-often smaller, with smaller brains -facial features include widely spaced eyes, underdeveloped upper jaw, flattened nose • Psychological characteristics appear to reflect dysfunction of the brain. • Maladaptive behaviors such as poor judgment, distractibility, and difficulty perceiving social cues are common. |
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Caffeine |
• Research regarding caffeine consumption is inconsistent -Several studies have found that pregnant women who take in a good deal of caffeine are more likely than nonusers to have a miscarriage or a low-birth-weight baby. |
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Cigarettes |
– Consist of nicotine, carbon monoxide, and hydrocarbons (tars) -Nicotine and carbon monoxide pass through placenta and reach the fetus -Nicotine stimulates the fetus; long-term effects unknown -Carbon monoxide decreases amount of oxygen available to the fetus -Connected with impaired motor development academic delays, learning disabilities, mental retardation, and hyperactivity • Smokers’ babies likely to be smaller than those of nonsmokers -Babies of smokers more likely to be stillborn or to die soon after birth • Men who smoke are more likely to produce abnormal sperm. -Babies of fathers who smoke have higher rates of birth defects, infant mortality, lower birth weights, and cardiovascular problems. |
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Parents’ Age |
Older fathers more likely to produce abnormal sperm • 20’s ideal age for women to bear children • Teenage pregnancy can result in higher incidence of infant mortality and low birth weight. • Stillborn or preterm babies increase as age of mother increases; adequate prenatal care decreases this likelihood even for first-time older mothers. |
