Chapter 3: Forming a New Life Flashcards
alleles
two or more alternative forms of a gene that occupy the same position on paired chromosomes and affect the same trait
autosomes
in humans, the 22 pairs of chromosomes not related to sexual expression
behavioral genetics
quantitative study of relative hereditary and environmental influences on behavior
canalization
limitation on variance of expression of certain inherited characteristics
cephalocaudal principle
principle that development proceeds in a head-to-tail direction, that is, that upper parts of the body develop before lower parts of the trunk
chromosomes
coils of DNA that consist of genes
concordant
term describing tendency of twins to share the same trait or disorder
dizygotic twins
twins conceived by the union of two different ova (or a single ovum that has split) with two different sperm cells; also called fraternal twins; they are no more alike genetically than any other siblings
dominant inheritance
pattern of inheritance in which, when a child receives different alleles, only the dominant one is expressed
Down syndrome
chromosomal disorder characterized by moderate-to-severe mental retardation and by such physical signs as a downward-sloping skin fold at the inner corners of the eyes (also called trisomy-21)
embryonic stage
second stage of gestation (2 to 8 weeks), characterized by rapid growth and development of major body systems and organs
epigenesis
mechanism that turns genes on or off and determines functions of body cells
fertilization
union of sperm and ovum to produce a zygote; also called conception
fetal alcohol syndrome (FAS)
combination of mental, motor, and developmental abnormalities affecting the offspring of some women who drink heavily during pregnancy
fetal stage
final stage of gestation (from 8 weeks to birth), characterized by increased differentiation of body parts and greatly enlarged body size
genes
small segments of DNA located in definite positions on particular chromosomes; functional units of heredity
genetic code
sequence of bases within the DNA molecule; governs the formation of proteins that determine the structure and functions of living cells
genetic counseling
clinical service that advises prospective parents of their probable risk of having children with hereditary defects
genotype
genetic makeup of a person, containing both expressed and unexpressed characteristics
genotype-environment correlation
tendency of certain genetic and environmental influences
to reinforce each other; may be passive, reactive (evocative), or active; also called genotype-environment covariance
genotype-environment interaction
the portion of phenotypic variation that results from the
reactions of genetically different individuals to similar environmental conditions
germinal stage
first 2 weeks of prenatal development, characterized by rapid cell division, blastocyst formation, and implantation in the wall of the uterus
gestation
period of development between conception and birth
gestational age
age of an unborn baby, usually dated from the first day of an expectant mother’s last menstrual cycle
heritability
statistical estimate of contribution of heredity to individual differences in a specific trait within a given population
heterozygous
possessing different alleles for a trait
homozygous
possessing two identical alleles for a trait
human genome
complete sequence of genes in the human body
implantation
the attachment of the blastocyst to the uterine wall, occurring at about day 6
incomplete dominance
pattern of inheritance in which a child receives two different alleles, resulting in partial expression of a trait
monozygotic twins
twins resulting from the division of a single zygote after fertilization; also called identical twins, they are genetically similar
multifactorial transmission
combination of genetic and environmental factors to produce certain complex traits
mutations
permanent alterations in genes or chromosomes that may produce harmful characteristics
niche-picking
tendency of a person, especially after early childhood, to seek out environments compatible with his or her genotype
nonshared environmental effects
the unique environment in which each child grows up,
consisting of distinctive influences or influences that affect one child differently than another
obesity
extreme overweight in relation to age, sex, height, and body type as defined by having a body mass index at or above the 95th percentile
phenotype
observable characteristics of a person
polygenic inheritance
pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait
proximodistal principle
principle that development proceeds from within to without, that is, that parts of the body near the center develop before the extremities
reaction range
potential variability, depending on environmental conditions, in the expression of a hereditary trait
recessive inheritance
pattern of inheritance in which child receives identical recessive alleles, resulting in expression of a nondominant trait
schizophrenia
mental disorder marked by loss of contact with reality; symptoms include hallucinations and delusions
sex chromosomes
pair of chromosomes that determines sex: XX in the normal human female, XY in the normal human male
sex-linked inheritance
pattern of inheritance in which certain characteristics carried on the X chromosome inherited from the mother are transmitted differently to her male and female offspring
spontaneous abortion
natural expulsion from the uterus of an embryo that cannot survive outside the womb (miscarriage)
stress
- physical or psychological demands on a person or organism
- response to physical or psychological demands
temperament
characteristic disposition, or style of approaching and reacting to situations
teratogen
environmental agent, such as a virus, a drug, or radiation, that can interfere with normal prenatal development and cause developmental abnormalities
ultrasound
prenatal medical procedure using high-frequency sound waves to detect the outline of a fetus and its movements, so as to determine whether a pregnancy is progressing normally.
zygote
one-celled organism resulting from fertilization
two or more alternative forms of a gene that occupy the same position on paired chromosomes and affect the same trait
alleles
in humans, the 22 pairs of chromosomes not related to sexual expression
autosomes
quantitative study of relative hereditary and environmental influences on behavior
behavioral genetics
limitation on variance of expression of certain inherited characteristics
canalization
principle that development proceeds in a head-to-tail direction, that is, that upper parts of the body develop before lower parts of the trunk
cephalocaudal principle
coils of DNA that consist of genes
chromosomes
term describing tendency of twins to share the same trait or disorder
concordant
twins conceived by the union of two different ova (or a single ovum that has split) with two different sperm cells; also called fraternal twins; they are no more alike genetically than any other siblings
dizygotic twins
pattern of inheritance in which, when a child receives different alleles, only the dominant one is expressed
dominant inheritance
chromosomal disorder characterized by moderate-to-severe mental retardation and by such physical signs as a downward-sloping skin fold at the inner corners of the eyes (also called trisomy-21)
Down syndrome
second stage of gestation (2 to 8 weeks), characterized by rapid growth and development of major body systems and organs
embryonic stage
mechanism that turns genes on or off and determines functions of body cells
epigenesis
union of sperm and ovum to produce a zygote; also called conception
fertilization
combination of mental, motor, and developmental abnormalities affecting the offspring of some women who drink heavily during pregnancy
fetal alcohol syndrome (FAS)
final stage of gestation (from 8 weeks to birth), characterized by increased differentiation of body parts and greatly enlarged body size
fetal stage
small segments of DNA located in definite positions on particular chromosomes; functional units of heredity
genes
sequence of bases within the DNA molecule; governs the formation of proteins that determine the structure and functions of living cells
genetic code
clinical service that advises prospective parents of their probable risk of having children with hereditary defects
genetic counseling
genetic makeup of a person, containing both expressed and unexpressed characteristics
genotype
tendency of certain genetic and environmental influences
to reinforce each other; may be passive, reactive (evocative), or active; also called genotype-environment covariance
genotype-environment correlation
the portion of phenotypic variation that results from the
reactions of genetically different individuals to similar environmental conditions
genotype-environment interaction
first 2 weeks of prenatal development, characterized by rapid cell division, blastocyst formation, and implantation in the wall of the uterus
germinal stage
period of development between conception and birth
gestation
age of an unborn baby, usually dated from the first day of an expectant mother’s last menstrual cycle
gestational age
statistical estimate of contribution of heredity to individual differences in a specific trait within a given population
heritability
possessing different alleles for a trait
heterozygous
possessing two identical alleles for a trait
homozygous
complete sequence of genes in the human body
human genome
the attachment of the blastocyst to the uterine wall, occurring at about day 6
implantation
pattern of inheritance in which a child receives two different alleles, resulting in partial expression of a trait
incomplete dominance
twins resulting from the division of a single zygote after fertilization; also called identical twins, they are genetically similar
monozygotic twins
combination of genetic and environmental factors to produce certain complex traits
multifactorial transmission
permanent alterations in genes or chromosomes that may produce harmful characteristics
mutations
tendency of a person, especially after early childhood, to seek out environments compatible with his or her genotype
niche-picking
the unique environment in which each child grows up,
consisting of distinctive influences or influences that affect one child differently than another
nonshared environmental effects
extreme overweight in relation to age, sex, height, and body type as defined by having a body mass index at or above the 95th percentile
obesity
observable characteristics of a person
phenotype
pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait
polygenic inheritance
principle that development proceeds from within to without, that is, that parts of the body near the center develop before the extremities
proximodistal principle
potential variability, depending on environmental conditions, in the expression of a hereditary trait
reaction range
pattern of inheritance in which child receives identical recessive alleles, resulting in expression of a nondominant trait
recessive inheritance
mental disorder marked by loss of contact with reality; symptoms include hallucinations and delusions
schizophrenia
pair of chromosomes that determines sex: XX in the normal human female, XY in the normal human male
sex chromosomes
pattern of inheritance in which certain characteristics carried on the X chromosome inherited from the mother are transmitted differently to her male and female offspring
sex-linked inheritance
natural expulsion from the uterus of an embryo that cannot survive outside the womb (miscarriage)
spontaneous abortion
- physical or psychological demands on a person or organism
- response to physical or psychological demands
stress
characteristic disposition, or style of approaching and reacting to situations
temperament
environmental agent, such as a virus, a drug, or radiation, that can interfere with normal prenatal development and cause developmental abnormalities
teratogen
prenatal medical procedure using high-frequency sound waves to detect the outline of a fetus and its movements, so as to determine whether a pregnancy is progressing normally.
ultrasound
one-celled organism resulting from fertilization
zygote
