fertilization

the process by which sperm and ovum combine to create a single cell called a zygote

cervix

opening of the uterus

genetic code

sequence of bases within the DNA molecule

chromosomes

coils of DNA that consist of genes

genes

functional units of heredity

DNA --> bases --> genes --> chromosomes

human genome

complete sequence of genes in the human body

sex chromosomes

the pair of chromosomes that determines sex

(XX or XY)

alleles

genes that can produce alternative expressions of a characteristic

homozygous

possessing two identical alleles for a trait

heterozygous

possessing different allels for a trait

dominant inheritance

pattern of inheritance in which, when an individual receives different alleles, only the dominant one is expressed

recessive inheritance

pattern of inheritance in which an individual receives identical recessive alleles, resulting in expression of a nondominant trait

polygenic inheritance

pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait

mutations

permanent alterations in genes or chromosomes that may produce harmful characteristics

phenotype

observable characteristics of a person

genotype

genetic makeup of a person, containing both expressed and unexpressed characteristics

multifactorial transmission

combination of genetic and environmental factors to produce certain complex traits

epigenesis

mechanism that turns genes on or off and determines functions of body cells

genome imprinting

the differential expression of certain genetic traits, depending on whether the trait has been inherited from the mother or the father

incomplete dominance

pattern of inheritance in which a child receives 2 different alleles, resulting in partial expression of a trait

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

down syndrome

chromosomal disorder caused by extra 21st chromosome or the translocation of part of the 21st chromosome onto another chromosome

genetic counseling

clinical service that advises prospective parents of their probable risk of having children with hereditary defects

behavioral genetics

quantitative study of relative hereditary and environmental influences on behavior

heritability

statistical estimate of contribution of heredity to individual differences in a specific trait within a given population

3 types of correlational research:

• family studies
• adoption studies
• twin studies

concordant

describes tendency of twins to share the same trait or disorder

reaction range

range of potential expressions of a hereditary trait

canalization

limitation on variance of expression of certain inherited characterisitics

genotype-environment interaction

the effects of similar environmental conditions on genetically different individuals

genotype-environment correlation

tendency of certain genetic and environmental influences to reinforce each other

genotype-environment correlation works in 3 ways to strengthen the phenotypic expression of a genotypic tendency:

• passive correlations
• reactive (evocative) correlations
• active correlations

niche-picking

tendency of a person 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 shild differently than another

obesity

extreme overweight in relation to age, sex, height, and body type

temperament

characteristic disposition, or style of approaching and reacting to situation

schizophrenia

mental disorder marked by loss of contact with reality

gestation

period of development between conception and birth

gestational age

age of an unborn baby

3 stages of prenatal development:

• germinal
• embryonic
• fetal

embryonic disk

thickened cell mass from which the embryo begins to develop (cells cluster to one side of the blastocyst)

cell mass (embryonic disk) differentiates into 3 layers:

• endoderm
• mesoderm
• ectoderm

endoderm

lower layer

- will become digestive system, liver, pancreas, salivary glands, respiratory system

mesoderm

middle layer

- will become inner layer of skin, muscles, skeleton, excretory and circulatory systems

ectoderm

upper layer

- will becom outer layer of skin, nails, hair, teeth, nervous system

spontaneous abortion

(miscarriage)

natural expulsion from the uterus of an embryo that cannot survive outside of the womb

ultrasound

the use of high-frequency sound waves to detect the outline of a fetus and its movements

teratogenic

capable of causing birth defects

fetal alcohol syndrome

characterized by a combination of retarded growth, face and body malformations, and disorders of the CNS

AIDS

viral disease caused by HIV

- undermines effective functioning of the immune system

toxoplasmosis

infection caused by parasite harbored in the bodies of farm animals and cats

- can cause fetal brain damage, severely impaired eyesight or blindness, seiqures, miscarriage, stillbirth, or death of the baby

stress

physical or psychological demands on a person or organism

parturiton

process of uterine, cervical, and other changes preceding childbirth

3 stages of childbirth and length:

• first (12-14 hours)
• second (1-2 hours)
• third (10-60 minutes)

electronic fetal monitoring

mechanical monitoring of fetal heartbeat during labor and delivery

cesarean delivery

surgically remove baby from uterus through an incision in mother's abdomen

natural childbirth

method of childbirth that seeks to prevent pain by eliminating mother's fear through education about the physiology of reproduction and training in breathing and relaxatio nduring delivery

prepared childbirth

method of childbirth that uses instruction, breathing exercises, and social support to induce controlled physical responses to uterine contractions and reduce fear and pain

lamaze method

teaches expectant mothers to work actively with their bodies through controlled breathing

LeBoyer method

woman gives birth in a quiet room under low lights, to reduce stress, and the newborn is gently massaged to ease crying

Odent method

laboring mother is submerged in a pool of water

Bradley method

rejects all obstetrical procedures and other medical interventions