Chapter 3

Nature versus Nurture

The debate regarding the relative importance of genetics (nature) and environment (nurture) in determining human behavior and development.

Genotype

The genetic constitution of an individual, often in relation to a specific trait.

Passive Genotype

A situation in which biological parents provide both genes and the environment to their children.

Evocative Genotype

When inherited characteristics evoke responses from others in the environment, shaping the child's development.

Active Genotype

The process where individuals seek out environments that correspond to their genetic characteristics, also known as niche picking.

Minnesota Twin Study

A research study examining identical twins raised apart to understand the influence of genetics versus environment on behavior and personality.

Blastocyst

A structure formed in the early development of mammals, consisting of a ball of cells that leads to implantation in the uterus.

Zygote

A fertilized ovum which results from the union of sperm and egg, marking the beginning of a new organism.

Ectopic Pregnancy

A pregnancy that occurs outside the uterus, often in a fallopian tube, which is not viable and can be dangerous.

Prenatal Development

The development of the fetus during pregnancy, typically divided into germinal, embryonic, and fetal periods.

Gamet Cells

Reproductive cells involved in the formation of a zygote; includes sperm and ova.

Mitosis

A type of cell division that results in two daughter cells, each having the same number of chromosomes as the parent cell.

Meiosis

A type of cell division that reduces the chromosome number by half, producing four gametes, each with 23 chromosomes.

Implantation

The process by which a blastocyst attaches itself to the uterine lining, allowing for further development.

Neural Tube

A structure that forms during embryonic development, eventually becoming the spinal cord and brain.

Critical Period

A specific time during development when certain events must occur for normal development to happen.

Trimester

One of the three periods of approximately three months each into which pregnancy is divided.

Gestational Age

The age of the fetus or embryo, calculated from the first day of the mother's last menstrual period.

Teratogens

Agents or factors that can cause malformation or development issues in the fetus.

Placenta

An organ that develops during pregnancy to provide nutrients and oxygen to the growing fetus and remove waste.

Amniotic Sac

A fluid-filled sac that surrounds and protects the developing embryo or fetus in the uterus.

Umbilical Cord

A tube that connects the fetus to the placenta, carrying nutrients and oxygen from the placenta to the fetus and waste products from the fetus back to the placenta.