Child Development: Genetics and Prenatal Development Flashcards

Vocabulary practice flashcards generated from Child Development lecture slides covering ethics, biological components, genetics, inheritance, and prenatal stages.

Single Human Cell Composition

At the moment of conception, a single human cell receives roughly $25,000$ genes contained on $46$ chromosomes organized into $23$ pairs.

Gametes

The sex cells from the mother and father (sperm and ovum) that form a new cell at conception.

Zygote

The single new cell formed by the process of fertilization.

Genes

The basic units of genetic information.

DNA

Deoxyribonucleic acid molecules; the substance that genes are composed of that determines the nature and function of every cell in the body.

Chromosomes

Rod-shaped portions of DNA that are organized in $23$ pairs.

Mitosis

The process of cell division through which nearly all body cells come to contain the same $46$ chromosomes as the original zygote.

Meiosis

The process of cell division in which each gamete receives one of the two chromosomes that make up each of the $23$ pairs.

Monozygotic Twins

Twins who are genetically identical, formed when a single zygote splits.

Dizygotic Twins

Twins produced when two separate ova are fertilized by two separate sperm at roughly the same time.

Dominant Trait

A trait that is expressed when two competing traits are present.

Recessive Trait

A trait within an organism that is present, but is not outwardly expressed.

Genotype

The underlying combination of genetic material present (but not outwardly visible) in an organism.

Phenotype

An observable trait that actually is seen in an organism.

Homozygous

Inheriting from parents similar genes for a given trait.

Heterozygous

Inheriting from parents different forms of a gene for a given trait.

Phenylketonuria (PKU)

An inherited disorder where a child is unable to process the essential amino acid phenylalanine, which can accumulate to levels toxic to the brain.

Behavioral Genetics

The study of the effects of heredity on behavior and psychological development.

Down Syndrome

A genetic disorder produced by the presence of an extra chromosome on the $21\text{st}$ pair.

Fragile X Syndrome

A disorder produced by injury to a gene on the $X$ chromosome, leading to mild to moderate intellectual disability.

Sickle-Cell Anemia

A blood disorder named for the distorted, sickle shape of the red blood cells in affected individuals.

Tay-Sachs Disease

A fatal neurological disorder of early childhood that produces blindness, seizures, paralysis, and muscle degeneration prior to death.

Klinefelter's Syndrome

A disorder resulting from the presence of an extra $X$ chromosome that produces underdeveloped genitals, extreme height, and enlarged breasts.

Polygenic Inheritance

An inheritance pattern in which a combination of multiple gene pairs is responsible for producing a particular trait.

Reaction Range

The potential degree of variability in the actual expression of a trait due to environmental conditions.

Amniocentesis

A prenatal test identifying genetic defects by examining fetal cells drawn by a needle inserted into the amniotic fluid.

Chorionic Villus Sampling (CVS)

A test used to find genetic defects that involves taking samples of hair-like material surrounding the embryo.

Ultrasound Sonography

A process in which high-frequency sound waves scan the mother's womb to produce an image of the unborn baby for assessment.

Multifactorial Transmission

The determination of traits by a combination of both genetic and environmental factors, where genotype establishes a range for phenotype expression.

Transgenerational Epigenetic Inheritance

A process in which life experiences alter parts of DNA that switch individual genes on or off, with potential consequences passed on to offspring.

Adoption Study

A research design comparing an adopted child's traits to biological parents (to measure genetic contribution) and adoptive parents (to measure environmental contribution).

Schizophrenia Genetic Risk

The lifetime risk of developing schizophrenia increases with genetic closeness, ranging from $1Memory test card for lifetime risk based on genetic relationship, reaching$48\%$$ in monozygotic twins.

Female Reproductive Path of Fertilization

The sequential process where ovulation releases a mature ovum from the ovary, fertilization occurs in the fallopian tube to form a zygote, and a blastocyst implants in the uterus.

Germinal Stage

The first and shortest stage of prenatal development (fertilization to $2$ weeks), characterized by rapid cell duplication and attachment to the uterine wall.

Ectoderm

The outer embryonic layer that develops into the skin, sense organs, brain, and spinal cord.

Endoderm

The inner embryonic layer that develops into the digestive system, liver, and respiratory system.

Mesoderm

The middle embryonic layer that develops into muscles, blood, and the circulatory system.

Embryonic Stage

The period from $2$ weeks to $8$ weeks post-conception, during which the organism (embryo) grows to $1\text{ inch}$ long and develops rudimentary anatomy across three layers.

Fetal Stage

The period from $8$ weeks until birth, formally starting when major organs differentiate and body length increases $20\text{ times}$.

Teratogen

An environmental agent or factor that produces a birth defect during prenatal development.

Fetal Alcohol Spectrum Disorder (FASD)

A cognitive disorder caused by a pregnant mother consuming substantial quantities of alcohol, potentially resulting in intellectual disability and delayed growth.

Fetal Alcohol Effects (FAE)

A condition in which children display some, but not all, symptoms of FASD due to maternal alcohol consumption during pregnancy.