Ch. 2: Heredity, Prenatal Development, and Birth Flashcards
chromosomes
threadlike structures in the nuclei of cells that contain genetic material
autosomes
first 22 pairs of chromosomes
sex chromosomes
23rd pair of chromosomes that determines sex of the child
gene
group of nucleotide bases that provides specific set of biochemical instructions
genotype
person’s hereditary makeup
phenotype
physical, behavioral, and psychological features that results from the interaction between ones’s genes and the environment
alleles
variations of genes (usually dominant or recessive. sickle cell example)
homozygous
when alleles in a pair in the chromosome are the same
heterzygous
when alleles in a chromosome pair are different
incomplete dominance
one allele does not dominate another completely
Huntington’s Disease
progressive and fatal form of dementia caused by dominant alleles. An exception to general principles that most fatal genetic disorders are recessive.
behavioral genetics
branch of genetics that studies inheritance and behavioral psychology traits
polygenic inheritance
when phenotypes are the result of the combined activity of many separate genes
heritability coefficient
measure (derived from correlation coefficient) of the extent to which a trait or characteristic is inherited
niche-picking
deliberately seeking environments that are compatible to one’s genetic makeup
nonshared environmental influences
forces within a family that make siblings different from each other
zygote
fertilized egg, created when sperm cell penetrates egg
implantation
zygote burrows into the uterine wall and establishes connections with the woman’s blood vessels
germ disc
small cluster of cells near the center of the zygote that eventually develop into the baby
embryo
term given to zygote once it is completely embedded in the uterine wall
ectoderm
outer layer of the embryo, which becomes the hair, outer layer of skin, and nervous system
mesoderm
middle layer of the embryo, which becomes the muscles, bones, and circulatory system
endoderm
inner layer of the embryo, which becomes the lungs and digestive system
amnion
inner sac in which the developing child rests
cephalocaudal principle
a principle of physical growth that states that structures nearest the head develop first
proximodistal principle
principle of physical growth stating that structures nearest the center of the body develop first
Period of the fetus
Weeks 9-38
Cerebral Cortex
wrinkled surface of the brain that regulates many functions that are distinctly human
Vernix
substance that protects fetus’s skin during development
age of viability
typically seven months after conception
Teratogen
an agent that causes abnormal prenatal development (found in alcohol, aspirin, famously in Thalidomide, etc.)
chorionic villus sampling (CVS)
prenatal diagnostic technique that involves taking a sample of tissue from the placenta (genetic testing and can be used earlier than other techniques, 9 to 12 weeks after conception)
hypoxia
birth complication - umbilical blood flow is disrupted and the infant does not receive adequate oxygen