Chapter 2 - Biological Foundation

Front 1

niche-picking

Back 1

process of deliberately seeking environments that are compatible with one’s genetic makeup

Front 2

amniocentesis

Back 2

prenatal diagnostic technique that uses a syringe to withdraw a sample of amniotic fluid through the mother’s abdomen

Front 3

homozygous

Back 3

when the alleles in a pair of chromosomes are the same

Front 4

amniotic fluid

Back 4

fluid that surrounds the fetus

Front 5

infant mortality

Back 5

the number of infants out of 1,000 births who die before their first birthday

Front 6

spina bifida

Back 6

disorder in which the embryo’s neural tube does not close properly

Front 7

hypoxia

Back 7

a birth complication in which umbilical blood flow is disrupted and the infant does not receive adequate oxygen

Front 8

cerebral cortex

Back 8

wrinkled surface of the brain that regulates many functions that are distinctly human

Front 9

cesarean section

Back 9

surgical removal of an infant from the uterus through an incision made in the mother’s abdomen

Front 10

monozygotic twins

Back 10

the result of a single fertilized egg splitting to form two new individuals; also called identical twins

Front 11

autosomes

Back 11

first 22 pairs of chromosomes

Front 12

teratogen

Back 12

an agent that causes abnormal prenatal development

Front 13

extremely low birth weight

Back 13

newborns who weigh less than 1,000 grams (2.2 pounds)

Front 14

amnion

Back 14

inner sac in which the developing child rests

Front 15

nonshared environmental influences

Back 15

forces within a family that make siblings different from one another

Front 16

heterozygous

Back 16

when the alleles in a pair of chromosomes differ from each other

Front 17

cephalocaudal principle

Back 17

a principle of physical growth that states that structures nearest the head develop first

Front 18

dizygotic twins

Back 18

the result of two separate eggs fertilized by two sperm; also called fraternal twins

Front 19

genotype

Back 19

person's hereditary makeup

Front 20

incomplete dominance

Back 20

situation in which one allele does not dominate another completely

Front 21

very low birth weight

Back 21

newborns who weigh less than 1,500 grams (3.3 pounds)

Front 22

stress

Back 22

physical and psychological responses to threatening or challenging conditions

Front 23

embryo

Back 23

term given to the zygote once it is completely embedded in the uterine wall

Front 24

age of viability

Back 24

age at which a fetus can survive outside the womb because most of its bodily systems function adequately; typically at seven months after conception

Front 25

phenylketonuria (PKU)

Back 25

inherited disorder in which the infant lacks a liver enzyme

Front 26

ectoderm

Back 26

outer layer of the embryo, which becomes the hair, outer layer of skin, and nervous system

Front 27

germ disc

Back 27

small cluster of cells near the center of the zygote that eventually develop into the baby

Front 28

dominant

Back 28

Form of an allele whose chemical instructions are followed

Front 29

in vitro fertilization

Back 29

process by which sperm and an egg are mixed in a petri dish to create a zygote, which is then placed in a woman’s uterus

Front 30

fetal alcohol spectrum disorder

Back 30

disorder affecting babies whose mothers consumed large amounts of alcohol while they were pregnant

Front 31

ultrasound

Back 31

prenatal diagnostic technique that uses sound waves to generate an image of the fetus

Front 32

chromosomes

Back 32

threadlike structures in the nuclei of cells that contain genetic material

Front 33

mesoderm

Back 33

middle layer of the embryo, which becomes the muscles, bones, and circulatory system

Front 34

period of the fetus

Back 34

longest period of prenatal development, extending from the 9th until the 38th week after conception

Front 35

proximodistal principle

Back 35

principle of physical growth that states that structures nearest the center of the body develop first

Front 36

zygote

Back 36

fertilized egg

Front 37

Behavioral genetics

Back 37

the branch of genetics that studies the inheritance of behavioral and psychological traits

Front 38

chorionic villus sampling

Back 38

prenatal diagnostic technique that involves taking a sample of tissue from the placenta

Front 39

sex chromosomes

Back 39

23rd pair of chromosomes; these determine the sex of the child

Front 40

prenatal development

Back 40

the many changes that turn a fertilized egg into a newborn human

Front 41

gene

Back 41

group of nucleotide bases that provides a specific set of biochemical instructions

Front 42

low birth weight

Back 42

newborns who weigh less than 2,500 grams (5.5 pounds)

Front 43

preterm or premature

Back 43

babies born before the 36th week after conception

Front 44

sickle-cell trait

Back 44

disorder in which individuals show signs of mild anemia only when they are seriously deprived of oxygen; occurs in individuals who have one dominant allele for normal blood cells and one recessive sickle-cell allele

Front 45

phenotype

Back 45

physical, behavioral, and psychological features that result from the interaction between one's genes and the environment

Front 46

crowning

Back 46

appearance of the top of the baby’s head during labor

Front 47

endoderm

Back 47

inner layer of the embryo, which becomes the lungs and digestive system

Front 48

alleles

Back 48

variations of genes

Front 49

fetal medicine

Back 49

field of medicine concerned with treating prenatal problems before birth

Front 50

polygenic inheritance

Back 50

when phenotypes are the result of the combined activity of many separate genes

Front 51

Vernix

Back 51

substance that protects the fetus’s skin during development

Front 52

heritability coefficient

Back 52

a measure (derived from a correlation coefficient) of the extent to which a trait or characteristic is inherited

Front 53

recessive

Back 53

allele whose instructions are ignored in the presence of a dominant allele

Front 54

Huntington’s disease

Back 54

progressive and fatal type of dementia caused by dominant alleles

Front 55

placenta

Back 55

structure through which nutrients and wastes are exchanged between the mother and the developing child

Front 56

eugenics

Back 56

effort to improve the human species by letting only people whose characteristics are valued by a society mate and pass along their genes

Front 57

implantation

Back 57

step in which the zygote burrows into the uterine wall and establishes connections with the woman’s blood vessels

Front 58

umbilical cord

Back 58

structure containing veins and arteries that connects the developing child to the placenta

Front 59

deoxyribonucleic acid

Back 59

molecule composed of four nucleotide bases that is the biochemical basis of heredity

Front 60

cesarean section (C-section)

Back 60

surgical removal of an infant from the uterus through an incision made in the mother’s abdomen

Front 61

deoxyribonucleic acid (DNA)

Back 61

molecule composed of four nucleotide bases that is the biochemical basis of heredity

Front 62

preterm (premature)

Back 62

babies born before the 36th week after conception