units of hereditary information composed of dna. ____ direct cells to reproduce themselves and manufacture the proteins that maintain life.
cellular reproduction in which the cells nucleus duplicates itself with two new cells being formed
a specialized form of cell division that occurs to forms eggs and sperm
a single cell formed through fertilization
a persons genetic heritage; the actual genetic material
the way an individuals genotype is expressed in observed and measurable characteristics
a recessive gene exerts its influence only if the two genes of a pair are both recessive
when a mutated gene is carried on the x chromosome, the result is called
x-linked inheritance .
few characteristics of genes reflect the influence of only a single gene or pair of genes
chromosomally transmitted form of mental retardation, caused by the presence of an extra copy of chromosome 21
chromosomal disorder in which males have an extra x chromosome, making them xxy instead of xy
genetic disorder involving an abnormality in the x chromosome, which becomes constricted and often breaks
fragile x syndrome
chromosomal disorder in females in which either an x chromosome is missing, making the person xo instead of xx, or the second x chromosome is partially deleted
chromosomal disorder in which males have an extra y chromosome
genetic disorder in which an individual cannot properly metabolize an amino acid. if left untreated, it results in mental retardation and hyperactivity
genetic disorder that affects the red blood cells and occurs most often in people of african descent
a small sample of the placenta is removed. risk of limb deformity
chorionic villus sampling (CVS)
sample of amniotic fluid is withdrawn by syringe and tested for chromosomal or metabolic disorders.
measures three substances in the mothers blood
10-15 percent of couples in the us experience _____ which is defined as the inability to conceive a child after 12 months of regular intercourse without contraception
eggs and sperm are combined in a laboratory dish. if they are successfully fertilized they are transferred into the womans uterus
in vitro fertilization (IVF)
children who are adopted early in their lives are more likely to have positive outcomes than
children adopted later in life
in general, adopted children and adolescents are more likely to experience
psychological and school related problems than non adopted children
the field that seeks to discover the influence of hereditary and environment on individuals differences in human traits and development
a study in which the behavioral similarity of identical twins is compared with the behavioral similarity of fraternal twins
a study in which investigators seek to discover whether, in behavior and psychological characteristics, adoptive children are more like their adoptive parents, or more like their biological parents
correlations that exist when the natural parents, who are genetically related to the child, provide a rearing environment for the child.
passive genotype-environment correlation
correlations that exist when the childs genotype elicits certain type of physical and social environments
evocative genotype environment correlations
correlations that exist when children seek out environments they find compatible and stimulating
active (niche picking) genotype environment correlations
siblings common environmental experiences, such as their parents personalities and intellectual orientation, the family's socioeconomic status, and the neighborhood that they live in.
shared environmental experiences
the childs own unique experiences, both within the family and outside the family, that are not shared by another sibling. thus, experiences occurring within the family can be part of the ____ environment