Flashcards in Chapter 2- Genetic And Environmental Foundations Deck (114):
Rodlike structures in the nuclei of cells that store and transmit genetic information are called
Human chromosomes come in how many matching pairs?
Chromosomes are made up of a chemical substance called _______________. It looks like a twisted ladder and is composed of segments called ______________.
Deoxyribonucleic acid or DNA; gene
The process through which DNA duplicates itself so that each new body cell contains the same number of chromosomes is called
Sex cells (sperm and ovum), or ________, are formed through the process of _________, A division process which halves the number of chromosomes normally present in body cells
When the sperm and ova unite at conception, the cell that results is called a
Zygote which will again have 46 chromosomes
An event in which chromosomes next to each other break at one or more points along their length and exchange segments, so that genes from one are replaced by genes from another creating new hereditary combinations unique to the individual
Why is the genetic variability produced by meiosis important in an evolutionary sense?
The genetic variability produced by meiosis is adaptive: because it generates offspring that vary in phenotype, it increases the chances that at least some members of a species will cope successfully with ever-changing environments and will survive
The 22 matching pairs of chromosomes, which geneticist number from longest to shortest. Means not sex chromosomes
The 23rd pair of chromosomes, also called the sex chromosomes, determines the sex of the child. In females, this pair is called _______, whereas in males it is called _______.
This is the most common type of multiple birth, resulting from the release and fertilization of two ova. Genetically, they are no more alike than ordinary siblings
Fraternal, or dizygotic twins
Older maternal age, fertility drugs, and in vitro fertilization are major causes of this type of twinning
Fraternal or dizygotic twins
When a zygote that has started to duplicate separates into two clusters of cells that develop into two individuals, this type of multiple birth occurs. These twins have the same genetic makeup
Identical or monozygotic twins
This type of twinning may result from environmental influences like temperature changes, variations in oxygen levels, or late fertilization of the ovum
Identical or monozygotic twins
True or false: during the early years of life, children of single births are often healthier and develop more rapidly than twins
Two forms of each gene occur at the same place on the chromosomes, one inherited from the mother and one from the father. Each form of a gene is called an ________.
If the alleles from both parents are alike, the child is ___________ and will display the inherited trait. If the alleles inherited from the mother and father are different, then the child is __________, and relationships between the alleles determine the trait, or phenotype
In many heterozygotes pairings, this type of inheritance occurs: only one allele affects the child's characteristics, it is called dominant, and the second allele, which has no effect, is called recessive.
Heterozygous individuals with just one recessive allele can pass that trait to their children and they are called carriers of the trait
One of the most common recessive disorders, which affects the way the body breaks down proteins contained in many foods is called
Infants born with two recessive allele is lack an enzyme that converts one of the basic amino acids that make up proteins into a byproduct essential for body functioning. Without this and
enzyme, phenylalanine quickly builds to toxic levels that damage the central nervous system and by one year-old infants with PKU are permanently retarded
Name three dominant and three recessive characteristics
Dominant: dark hair, curly hair, facial dimples, farsightedness, type a blood, double-jointedness
Recessive blonde hair, pattern baldness, red hair, nearsightedness, albinism, type O blood
These type of genes enhance or dilute the effects of other genes
True or false: serious diseases typically result from dominant alleles
False, only rarely are serious diseases due to dominant alleles. Children who inherit the dominant allele always develop the disorder and they seldom live long enough to reproduce, so the harmful dominant allele is eliminated from the families heredity in a single generation
A pattern of inheritance in which both alleles are expressed in the phenotype, resulting in a combined trait, or one that is intermediate between the two.
What is one condition that results from this pattern of inheritance?
The sickle cell trait, a heterozygous condition present in many black Africans. Sickle cell anemia occurs in full form when a child inherits two recessive allele's which cause their usually round blood cells to become sickle or crescent moon shaped, especially under low oxygen conditions. The sickle cell clogs the blood vessels and blocks the flow of blood, causing intense pain, swelling, and tissue damage
When a harmful allele is carried on the X chromosome, this type of inheritance applies. Are males or females more likely to be affected and why?
X-linked inheritance. Males are more likely to be affected because their sex chromosomes do not match. In females, any recessive allele on one X-chromosome has a good chance of being suppressed by dominant alleles on the other X. But the Y chromosome is only about one third as long and therefore lacks many corresponding alleles to override those on the X
Name one X linked disorder
Hemophilia, a disorder in which the blood fails to clot normally. More likely in males
In recent decades, the proportion of male births has declined in many industrialized countries. Briefly explain why
Some researchers attribute the trend to a rise in stressful living conditions, which heighten spontaneous abortions, especially of male fetuses
When alleles are chemically marked in such a way that one pair member is activated, regardless of its make up
List three conditions or diseases that are caused by genomic imprinting
Diabetes, asthma, hayfever, Prader-Willi syndrome, Huntington disease, fragile X syndrome
This is how harmful jeans are created. A sudden but permanent change in a segment of DNA.
Some mutations ocher spontaneously simply by chance and others are caused by hazardous environmental agents
Characteristics that vary on a continuum among people, such as height, weight, intelligence, and personality. These traits are due to this type of inheritance, in which many genes affect the characteristic in question
Most chromosomal defects are the result of mistakes during ________, when the ovum and sperm are formed
This is the most common chromosomal abnormality, which often results from a failure of the 21st pair of chromosomes to separate during meiosis. For this reason, the disorder is sometimes called ________ __
Down syndrome; trisomy 21
What are the physical and behavioral characteristics of down syndrome
Physical: a short, stocky build; a flattened face; A protruding tongue; almond-shaped eyes; and an unusual crease running across the palm of the hand
Mental: mental retardation, memory and speech problems, limited vocabulary, and slow motor development
True or false: the risk of down syndrome rises with maternal age
Do disorders of the sex chromosomes result in more or less serious consequences than disorders of the autosomes
Disorders of the autosomes usually disrupt development so severely that miscarriage occurs and when such babies are born, they rarely survive beyond early childhood. In contrast, abnormalities of the sex chromosomes usually lead to fewer problems and some are not recognized until adolescence when, in some deviations, puberty is delayed
True or false: males with XYY syndrome are more aggressive and antisocial then XY males
True or false: most children with sex chromosome disorders suffer from mental retardation
True or false: girls with Turner syndrome have trouble with spatial relationships, such as drawing pictures and noticing changes in facial expressions
True or false: children with a sex chromosome disorder have intellectual problems that are usually very specific
_________ are directly observable characteristics that dependent in part on the _________, The complex blend of genetic information that determines our species and also influences all of our unique characteristics
A communication process designed to help couples assess their chances of giving birth to a baby with a hereditary disorder and choose the best course of action in view of risks and family goals
Who is most likely to seek genetic counseling?
Those who have had difficulties bearing children, for example repeated miscarriages, or who know that genetic problems exist in their families. Women who delay childbearing past age 35.
Medical procedures that permit detection of developmental problems before birth
Prenatal diagnostic methods
The most widely used prenatal diagnostic method where a hollow needle is inserted through the abdominal wall to obtain a sample of fluid in the uterus. Cells are examined for genetic defects
A procedure that can be used if results are desired or needed very early in pregnancy. A thin tube is inserted into the uterus through the vagina, or a hollow needle is inserted through the abdominal wall. A small plug of tissue is removed from the end of one or more chorionic villa, the hair-like projections on the membrane surrounding the developing organism and cells are examined for genetic defects
Chorionic villus sampling
With this prenatal diagnostic method, a small tube with a light source at one end is inserted into the uterus to inspect the fetus for defects of the limbs and face. Also allows a sample of fetal blood to be obtained, permitting diagnosis of such disorders as hemophilia and sickle cell anemia as well as neural defects
With this pre-natal diagnostic method, high-frequency sound waves are beamed at the uterus; the reflection is translated into a picture on a video screen that reveals the size, shape, and placement of the fetus. By itself, permits assessment of fetal age, detection of multiple pregnancies, and identification of gross physical defects.
With this prenatal diagnostic method, by the second month of pregnancy, some of the developing organism cells enter the maternal blood stream. And elevated level of alpha-fetoprotein protein may indicate kidney disease, abnormal closure of the esophagus, or neural tube defect's, such as anencephaly and spina bifida. Isolated cells can be examined for genetic defects
Maternal blood analysis
With this type of prenatal diagnostic method, after in vitro fertilization and duplication of the zygote into a cluster of about 8 to 10 cells, one or two cells are removed and examined for hereditary defects. Only if that sample is free of detectable genetic disorders is the fertilized ovum implanted in the woman's uterus
Pre-implantation genetic diagnosis
True or false: the techniques used in fetal medicine generally cause no harm to the developing fetus
Summarize the goals of the human genome project, and explain why this program offers hope for correcting hereditary defects
Researchers have mapped the sequence of all human DNA base pairs. Using this information, they are identifying all its genes and their functions, including their protein products and what these products do. A major goal is to understand the estimated 4000 human disorders, those due to single genes and those resulting from a complex interplay of multiple genes and environmental factors. New treatments are being explored, such as gene therapy
Describe three steps that prospective parents can take before conception to increase their chances of having a healthy baby
Arrange for a physical exam-permits detection of diseases and other medical problems that might reduce fertility, be difficult to treat during pregnancy, or affect the developing organism
Reduce or eliminate toxins under your control- avoid drugs, alcohol, cigarettes smoke, radiation, pollution, chemical substances in the home and workplace, and infectious disease is. Stay away from ionizing radiation and some industrial chemicals
Ensure proper nutrition-a doctor recommended vitamin mineral supplement, begun before conception, helps prevent many prenatal problems. Should include folic acid.
Injection of sperm from an anonymous man into a woman. Used to overcome male reproductive difficulties and has also permitted women without a male partner to become pregnant. 70 to 80% successful
A woman is given hormones that stimulate the ripening of several ova. These are removed surgically and placed in a dish of nutrients, to which sperm are added. Once an ovum is fertilized and begins to duplicate into several cells, it is injected into the mother's uterus. 1% of all children in developed countries, about 40,000 babies in the United States, have been conceived through this technique annually
In Vitro fertilization
This reproductive technology is usually used to treat women whose fallopian tube's are permanently damaged
In vitro fertilization
Which reproductive technology use as a sexy order method to help ensure that couples who carry X-linked diseases have a daughter
In vitro fertilization
With this reproductive technology, the rate of low birth weight is nearly 3 times as high as in the general population
In vitro fertilization
In this reproductive procedure, in vitro fertilization may be used to impregnate a woman with the couples fertilized ovum. Alternatively, sperm from a man whose partner is infertile may be used to inseminate the woman, who agrees to turn the baby over to the natural father. The child is then adopted by his partner and the woman is paid a fee for her childbearing services
Surrogate mother hood
This reproductive method is one of the most controversial forms of medically assisted conception and may promote exploitation of financially needy women
Surrogate mother hood
Briefly describe new reproductive options being explored by researchers, as well as the ethical debates surrounding them
Doctors have used doner ova from younger women in combination with in vitro fertilization to help postmenopausal women become pregnant. Raises questions about bringing children into the world whose parents may not live to see them reach adulthood
At donor banks, customers can select ova or sperm on the basis of physical characteristics and even IQ. Scientists are devising ways to alter the DNA of human ova, sperm, and embryos to protect against hereditary disorders, techniques that could be used to engineer other desired characteristics. Many wary that these practices are dangerous steps toward selective breeding through designer babies, controlling offspring traits by manipulating genetic make up
Do adopted children and adolescents have fewer or more learning and emotional difficulties than other children? Cite three possible reasons for this trend
Adopted children and adolescents tend to have more learning and emotional difficulties than other children.
Reasons: The biological mother may have been unable to care for the child because of problems believed to be partly genetic, such as alcoholism or severe depression, and may have passed this tendency to her offspring. Biological mother may have experience stress, poor diet, or in adequate medical care during pregnancy-factors that can affect the child. Children adopted after infancy often have a pre-adoptive history of conflict ridden family relationships, lack of parental affection, neglect and abuse, or deprived institutional rearing. Adoptive parents and children, who are genetically unrelated, are less alike in intelligence and personality than are biological relatives-differences that may threaten family harmony
Discuss research findings on international adoptees' development in comparison to birth siblings or age mates who stay behind
International adoptees fare much better in development than birth siblings or institutionalized agemates who stay behind.
True or false: adoptees usually begin the search for their birth parents during early adolescence
False, the decision to search for birthparents is usually postponed until early adulthood, when marriage and childbirth may trigger it
When a marital relationship is warm and considerate, mothers and fathers are more likely to engage in this where they mutually support each other's parenting behaviors
Parent to coparent our warmer, praise and stimulate children more, and nag and scold them less. Parents whose marriages are tense and hostile often interfere with one another's child rearing efforts, are less responsive to children's needs, and are more likely to criticize, express anger, and punish. Children who are chronically exposed to angry, unresolved parental conflict have serious emotional problems resulting from disrupted emotional security including internalizing difficulties and externalizing difficulties
Discuss some ways in which the family system must adapt overtime
As children acquire new skills, parents adjust the way they treat their more competent youngsters
Parents development affects children as well. While the adolescent presses for more autonomy, the parent presses for more togetherness as they know they will soon leave home. This imbalance promotes friction, which parent and teenager gradually resolve by accommodating to changes in each other
List the three variables that determine a family's socioeconomic status
Years of education, the prestige of one's job and the skill it requires (social status), income, which measures economic status
What child characteristics are emphasized in lower SES families and in higher SES families?
Lower SES parents tend to emphasize external characteristics, such as obedience, politeness, neatness, and cleanliness
Higher SES parents tend to emphasize psychological traits, such as curiosity, happiness, self-direction, and cognitive and social maturity
Describe the influences of SES on parenting practices and parent child interaction
Parents higher in SES talk to , read to, and otherwise stimulate their infants and preschoolers more and grant them freedom to explore. With older children and adolescents, higher SES parents use more warmth, explanations, and verbal praise; set higher academic and other developmental goals; and allow their children to make more decisions
In the low SES households, commands, criticism, and physical punishment all occur more often
What are several factors that explain SES differences in family interaction?
Education-higher SES parents' interest in providing verbal stimulation, nurturing inner traits, and promoting academic achievement is supported by years of schooling, during which they learn to think about abstract, subjective deas. Education of women in particular foster's patterns of thinking and behaving that greatly improve quality-of-life for both parents and children
Because of limited education and low social status, many lower SES parents feel a sense of powerlessness and lack of influence in their relationships. Higher levels of stress, along with a stronger belief in the value of physical punishment, contribute to low SES parents greater use of coercive discipline whereas higher SES parents typically have more control over their own lives and they teach these skills to their children
True or false: higher SES children show more advances in cognitive development and tend to perform better in school than their lower SES peers
Cite two ways that educating girls benefits the welfare of families, societies, and future generations
Through enhanced verbal skills including reading, writing, and oral communication. Through empowerment, a growing desire to improve their life conditions
When it comes to the worldwide education of girls, how does education influence family health?
Education gives people the communicative skills and confidence to seek health services and to benefit from public health information. Years of schooling strongly predicts women's preventative health behavior, prenatal visits, child immunizations, healthy diet, and sanitary practices. More likely to take advantage of family-planning services, delay marriage and childbearing, and have more widely spaced and fewer children. This is linked to increased maternal and Child survival and family health
True or false: the empowerment that education provides women is associated with more equitable husband-wife relationships and a reduction in harsh disciplining of children
What are two factors that contribute to poor adjustment in affluent youths?
When children in affluent families lack of parental supervision and emotional closeness
What simple routine is associated with a reduction in adjustment difficulties for both affluent and low SES youths?
Eating dinner with parents
What for subgroups of the population are hardest hit by poverty?
Parents under age 25 with young children, elderly people who live alone, ethnic minorities, and women
Is the poverty rate higher or lower among children than any other group and why
It is higher among children than any other age group due to joblessness, a high divorce rate, a high rate of adolescent parenthood, and inadequate government programs to meet family needs
What are some of the long-term consequences of childhood poverty?
suffer from lifelong poor physical health, persistent deficits in cognitive development and academic achievement, high school dropout, mental illness, and impulsivity, aggression, and antisocial behavior
How do the constant stressors that accompany poverty gradually weaken the family system?
May have many daily hassles, bills to pay, the car breaking down for example and when these daily crises arrive, family members become depressed, irritable, and distracted; hostile interactions increase; children's development suffers. Families who must live in poor housing and dangerous neighborhood have higher negative outcomesdue to reduced social support
Why has the number of homeless children risen in the past 30 years and what are the challenges that these children face?
Mostly due to two factors, a decline in the availability of government supported low-cost housing, and the release of large numbers of mentally ill people from hospitals without an increase in community treatment programs to help them adjust to ordinary life and get better
Many homeless children suffer from developmental delays and chronic emotional stress due to their harsh, insecure daily lives. Many do not go to school and those who do achieve less than other children because of poor attendance and health and emotional difficulties
Do neighborhood resources have a greater impact on children growing up in disadvantaged or well-to-do areas and why?
Neighborhood resources have a greater impact on economically disadvantaged than on well to do young people
Hire SES families are less dependent on their immediate surroundings for social support, education, and leisure pursuits. They can afford to transport their children to lessons and entertainment and to better quality schools.
What are four benefits that family-neighborhood ties have on promoting positive development?
Parental self-worth: a neighbor or relative who listens and tries to relieve a parents concerns enhances her self-esteem and then the parent is likely to interact in a more sensitive and involved matter with her children
Parental access to valuable information and services: where to find a job, housing, and affordable childcare and youth activities helps make the multiple roles of spouse, parent, and provider easier to fulfill
Child-rearing controls and role models: friends, relatives, and other community members may encourage and demonstrate effective parenting practices and discourage in effective practices
Direct assistance with child rearing: other adults can influence children through warmth, stimulation, and exposure to a wider array of competent models and help to reduce the impact of an effective parenting. Nearby adults can also intervene when they see young people skipping school or behaving antisocially
List 3 broad features of the school environment that affect students' developmental outcomes
Physical environments: student body size, Number of children per class, and space available for work and play
The social life of schools
Why are higher SES parents more likely to have regular contact with teachers then lower SES parents?
Because hire SES parents have backgrounds and value similar to those of teachers. Low SES and ethnic minority parents often feel uncomfortable about coming to school, and daily stressors reduce the energy they have for school involvement
Groups of people with beliefs and customs that differ from those of the larger culture
The African-American ______-______ household, in which one or more adult relatives live with the parent-child nuclear family unit, is a vital feature of black family life
These types of societies, people defined themselves as part of a group and stress group over individual goals
In these types of societies, people think of themselves as separate entities and are largely concerned with their own personal needs
Laws and government programs designed to improve current conditions
What are three reasons why attempts to help children and youths in the United States have been difficult to realize?
A complex set of political and economic forces is involved. Cultural values of self-reliance and privacy have made government has a tent to become involved in family matters. Good social programs are expensive, and they must compete for a fair share of a country's economic resources
A legal agreement among nations that commits each cooperating country to work toward guaranteeing environments that foster children's development, protect them from harm, and enhance their community participation and self-determination
The convention on the rights of the child
Although the United States played a key role in drying up the convention, it is one of only two countries in the world who is legislature has not yet ratified it
What are the characteristics of the African-American extended family that help reduce the stress of poverty and single parenthood?
Extended-family members often help with child rearing, and adolescent mothers living in extended families are more likely to complete high school and get a job and less likely to be on welfare then mothers living on their own, factors that benefit children's well-being
How does the African-American extended family help transmit cultural values?
Extended family arrangements place more emphasis on cooperation and on moral and religious values. Older black adults, such as grandparents and great grandparents, regarding educating children about their African heritage as especially important. Family reunions are common, giving young people a strong sense of their roots which strengthen family bonds, enhance children's development, and increase the chances that the extended family lifestyle will carryover to the next generation
A field devoted to uncovering the contributions of nature and nurture to the diversity in human traits and abilities
Name the two methods used by behavioral geneticists to infer the role of heredity in complex human characteristics
Heritability estimates and kinship studies
Measures the extent to which individual differences in complex traits in a specific population are due to genetic factors
Studies which compare the characteristics of family members, The most common type compares identical twins, who share all their jeans, with fraternal twins, who share only some
Heritability estimates are obtained from kinship studies
True or false: heritability estimates for intelligence and personality are approximately .50, indicating that genetic makeup can explain half of the variance in the traits
What are three limitations of heritability estimates?
The accuracy: depends on the extent to which the twin pair studied reflect genetic and environmental variation in a population-most twin pairs are your rear together under highly similar conditions and even when separated, social service agencies place them in advantage homes that are alike in many ways. Because the environments of most twin pairs are less diverse than those of the general population, heritability estimates are likely to exaggerate the role of heredity
Can easily be misapplied: high heritabilities have been used to suggest that ethnic differences in intelligence have a genetic basis yet this line of reasoning is widely regarded as incorrect
Limited usefulness: though interesting, these estimates give us no precise information on how intelligence and personality develop or how children might respond to environments designed to help them develop as far as possible
Each person's unique, genetically determined response to the environment
Range of reaction
The tendency of heredity to restrict the development of some characteristics to just one or a few outcomes
In range of reaction, heredity ___________ responsiveness to varying environment. In canalization, heredity _________ the development of certain behaviors
Range of reaction highlights two important points, what are they?
Shows that because each of us has a unique genetic make up, we respond differently to the same environment
Sometimes different genetic-environmental combinations can make two people look the same
What is an example of a strongly canalized behavior?
Infant perceptual and motor development seems to be strongly canalized because all the normal human babies eventually rollover, reach for objects, sit up, crawl, and walk
According to this concept, our genes influence the environments to which we are exposed
With this type of genetic-environmental correlation, the child has no control over it, parents provide environments influenced by their own heredity
Example parents who are good athletes emphasize outdoor activities and enroll their children in swimming and gymnastics
With this type of genetic-environmental correlation, A child's style of responding influences others responses, which then strengthens the child's original style
Example, and active, friendly baby is likely to receive more social stimulation then a passive, quiet infant
With this type of genetic-environmental correlation, children increasingly seek out environments that fit their genetic tendencies, also called niche-picking
Example, the musically talented child joins the school orchestra and practices his violin
The tendency to actively choose environments that complement our heredity is called
_________ means development resulting from ongoing, bidirectional exchanges between heredity and all levels of the environment. Researchers call this view of the relationship between heredity and the environment the _________ framework
Epigenesis; Epigenetic framework
Provide an example of epigenesis
Providing a baby with a healthy diet promotes brain growth, leading to new connections among nerve cells, which transform gene expression. This opens the door to new gene-environmental exchanges-for example, advanced exploration of objects and interaction with caregivers, which further enhance brain growth and Gene expression. These ongoing bidirectional influences foster cognitive and social development
Maternal smoking during pregnancy is among the risk factors for this, one of the most common disorders of childhood
Attention-deficit hyperactivity disorder or, ADHD
What does animal research reveal about environmental influences associated with ADHD?
Environmental influences associated with ADHD, such as prenatal exposure to toxins, modify the genes activity.
Tobacco smoke stimulates the DD genotype to release chemicals in the brain that promote impulsivity and overactivity, these behaviors often even Okarche, punitive parenting, which can trigger defiance in children