DVP - Chapter 3

• Union of sperm and ovum to produce a

  zygote; also called conception.

  Fertilization
• One-celled organism resulting from

  fertilization.

  Zygote
• Methods

  used to achieve conception through artificial means.

  Assistive Reproductive Technology (ART)
• 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
• Twins resulting from the

  division of a single zygote after fertilization; also called

  identical twins; they are genetically similar.

  Monozygotic Twins
• carries inherited instructions for the development of all

  cellular forms of life.

  Deoxyribonucleic Acid (DNA)
• Sequence of bases within the DNA

  molecule; governs the formation of proteins that

  determine the structure and functions of living cells.

  Genetic Code
• Coils of DNA that consist of genes.

  genes Small segments of DNA located in definite

  positions on particular chromosomes; functional units

  of heredity.

  Chromosomes
• Complete sequence of genes in the

  human body.

  Human Genome
• Permanent alterations in genes or

  chromosomes that may produce harmful

  characteristics.

  Mutations
• In humans, the 22 pairs of chromosomes

  not related to sexual expression.

  Autosomes
• Pair of chromosomes that

  determines sex: XX in the normal human female, XY

  in the normal human male

  Sex Chromosomes
• Pair of chromosomes that

  determines sex: XX in the normal human female, XY

  in the normal human male

  Sex Chromosomes
• Two or more alternative forms of a gene that

  occupy the same position on paired chromosomes and

  affect the same trait.

  Alleles
• Possessing two identical alleles for a

  trait.

  Homozygous
• Possessing differing alleles for a trait.

  Heterozygous
• Pattern of inheritance in

  which, when a child receives different alleles, only the

  dominant one is expressed.

  Dominant Inheritance
• Pattern of inheritance in

  which a child receives identical recessive alleles,

  resulting in expression of a nondominant trait.

  Recessive Inheritance
• Pattern of inheritance in

  which multiple genes at different sites on chromosomes

  affect a complex trait.

  Polygenic Inheritance
• Observable characteristics of a person.

  Phenotype
• Genetic makeup of a person, containing both

  expressed and unexpressed characteristics.

  Genotype
• Combination - of genetic

  and environmental factors to produce certain complex

  traits.

  Multifactorial Transmission
• that turns genes on or off and

  determines functions of body cells.

  Epigenesis Mechanism
• 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
• Clinical service that advises

  prospective parents of their probable risk of having

  children with hereditary defects.

  Genetic Counseling
• Quantitative study of relative

  hereditary and environmental influences on behavior.

  Behavioral Genetics
• estimate of contribution of

  heredity to individual differences in a specific trait

  within a given population.

  Heretability Statistic
• Term describing tendency of twins to

  share the same trait or disorder.

  Concordant
• depending on

  environmental conditions, in the expression of a

  hereditary trait.

  Reaction Range Potential Variability
• Limitation on variance of expression of

  certain inherited characteristics.

  Canalization
• The portion of

  phenotypic variation that results from the reactions of

  genetically different individuals to similar

  environmental conditions.

  Genotype-Environment Instruction
• 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
• 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
• Characteristic disposition, or style of

  approaching and reacting to situations.

  Temperament
• Mental disorder marked by loss of

  contact with reality; symptoms include hallucinations

  and delusions.

  Schizophrenia
• 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
• 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