Human Development and Genetics

These flashcards encompass key vocabulary and concepts from human development, genetics, and associated theories as covered in the lecture notes.

Sperm

Sex cell of male, responsible for transferring male genetic material to the egg.

Egg Cell

Female reproductive cell, significantly larger than sperm, containing genetic material and a thick outer coating (zona pellucida).

Fertilization

The process when sperm meets the egg, consisting of sperm binding, acrosome reaction, cortical reaction, and genetic transfer.

Acrosome Reaction

Process where enzymes from the sperm leak into the zona pellucida to digest it, allowing sperm to approach the egg's plasma membrane.

Cortical Reaction

Process where enzymes from the egg digest the zona pellucida to prevent polyspermy.

Blastocyst

Stage of embryo development consisting of an inner cell mass and a blastocoel, occurring after the zona pellucida disintegrates.

Gastrulation

Process of cell migration and formation of germ layers: ectoderm, mesoderm, and endoderm.

Neurulation

Development of the notochord and formation of the neural tube from the ectoderm.

Gestation

Period of development from fertilization to birth, typically lasting about nine months.

Motor Milestones

Key physical skills developed during early childhood, such as rolling over, sitting up, crawling, and walking.

Reflexes

Automatic, involuntary responses to stimuli, important for newborns to interact with their environment.

Adolescence

Transition period between childhood and adulthood characterized by physical and psychological changes.

Puberty

Period of sexual maturation, typically starting around 11-13 years for girls and 13-14 years for boys.

Heredity

Passing of traits from parents to offspring through genes.

Genes

Units of heredity made up of segments of DNA that control traits and characteristics.

Temperament

Characteristic emotional reactivity and intensity of an individual, considered to be established early in life.

Heritability

The extent to which variations in a trait can be attributed to genetic differences among individuals.

Epigenetics

Study of changes in gene expression that do not involve changes to the DNA sequence itself.

Gene-Environment Interaction

The way in which genetic predispositions and environmental factors influence behavior.

Adaptive Value

The usefulness of a behavior for an organism's survival and maintenance of homeostasis.

Positive Feedback

Process that amplifies production of a product.

Negative Feedback

Process that reduces or inhibits production of a product to maintain balance.

Instincts

Innate, biological tendencies that dictate behavior.

Drive Reduction Theory

Motivational theory suggesting that behavior arises from physiological needs that create drives.

Cognitive Theories of Motivation

Focus on how cognitive processes influence motivation and behavior.

Cleavage

The series of rapid mitotic cell divisions following fertilization where the total volume of the conceptus remains constant while the number of cells increases, enhancing the surface area-to-volume ratio for gas and nutrient exchange.

Morula

A solid ball of cells resulting from cleavage, typically consisting of 16 to 32 cells, occurring before the formation of the blastocoel.

Blastocyst Components

1. Trophoblast: Outer cell layer that becomes the chorion and later the placenta.
2. Inner Cell Mass (ICM): Internal cluster of cells that eventually forms the embryo and extraembryonic membranes.

Ectoderm Derivatives

The "attract-oderm" gives rise to the nervous system (including the adrenal medulla), epidermis, hair, nails, and the epithelia of the nose, mouth, and lower anal canal.

Mesoderm Derivatives

The "means-oderm" gives rise to the musculoskeletal system, circulatory system, excretory system, gonads, connective tissue, and the adrenal cortex.

Endoderm Derivatives

The "endernal" lining provides the epithelial linings of the digestive and respiratory tracts, the bladder, and distal urinary tracts, as well as the liver and pancreas.

Neural Crest Cells

Cells located at the tip of each neural fold during neurulation that migrate throughout the body to form the peripheral nervous system (PNS), including sensory ganglia, autonomic ganglia, adrenal medulla, and Schwann cells.

Yerkes-Dodson Law

A principle stating that performance is optimal at an intermediate level of arousal, following a U-shaped function; high or low levels of arousal results in poor performance.

Maslow’s Hierarchy of Needs

A theory that categorizes human needs into five levels that must be met sequentially:

1. Physiological (Survival)
2. Safety (Security)
3. Love/Belonging (Social)
4. Esteem (Respect)
5. Self-Actualization (Full Potential)

Incentive Theory

A behavioral theory suggesting that motivation is driven by a desire to pursue external rewards and avoid punishments, rather than internal biological drives.

Twin Study Methodology

Utilizes Monozygotic (MZ) twins who share 100\% of DNA and Dizygotic (DZ) twins who share 50\% of DNA to estimate heritability (h^2) by comparing concordance rates.