The Cell Cycle, Mitosis, Meiosis, and Chromosomal Disorders

Vocabulary flashcards defining key terms regarding the cell cycle phases, mitosis, meiosis, cell cycle disorders, and chromosomal abnormalities.

Cell Division

The process by which a parent cell divides into two or more daughter cells, usually occurring as part of a larger cell cycle.

Mitosis

The process that cells use to make exact replicas of themselves, observed in almost all body cells including eyes, skin, hair, and muscle cells.

Meiosis

A special type of cell division in reproductive cells that produces sperm or egg cells (gametes) with a haploid set of chromosomes ($2n \rightarrow n$), dividing twice to form four genetically unique cells.

Interphase

A primary phase in the cell cycle, previously thought to represent a resting stage but shown by research to be a very active phase where the cell grows and DNA is replicated.

$G_0$ Phase (Resting Phase)

A phase in the cell cycle where the cell neither divides nor prepares itself for division.

$G_1$ Phase (Gap 1)

A phase of the cell cycle where the cell is metabolically active and grows continuously.

S Phase (Synthesis)

The stage of the cell cycle during which DNA replication or synthesis occurs.

$G_2$ Phase (Gap 2)

The phase of the cell cycle where protein synthesis happens.

M Phase (Mitosis Phase)

The phase of the cell cycle where actual cell division occurs, consisting of cytokinesis and karyokinesis, and divided into Prophase, Metaphase, Anaphase, and Telophase.

Prophase

The stage of mitosis where chromosomes condense, spindle fibers form from centrioles, and chromosomes are captured by the spindle.

Spindle Fibers

Specialized microtubules radiating out from centrioles during cell division.

Metaphase

The stage of mitosis where chromosomes align along the equator of the cell, with each chromatid attached to the spindle by a kinetochore facing each pole.

Kinetochore

A structure in the centromere by which each chromatid is attached to the spindle.

Anaphase

The stage of mitosis where chromatids separate, spindle fibers shorten, and chromosomes are pulled apart equally to opposite sides of the cell.

Telophase

The stage of mitosis where the cell builds two nuclei around separated chromosomes, chromosomes de-condense, and nuclear envelopes reform to prepare for division.

Cancer

A broad group of diseases characterized by the uncontrolled growth and spread of cells.

Ciliopathies

A diverse group of genetic disorders caused by defects in the structure or function of cilia, which are hair-like organelles found on nearly all human cells.

Alzheimer's Disease

A progressive, neurodegenerative brain disorder that accounts for the vast majority of dementia cases.

Parkinson's Disease

A progressive, neurodegenerative disorder of the central nervous system that primarily affects movement.

Chromosomal Disorder

Any syndrome characterized by malformations or malfunctions in body systems, caused by an abnormal chromosome number or constitution.

Trisomy

A genetic condition that results in an extra copy of a chromosome, giving a person $47$ chromosomes instead of $46$.

Trisomy $13$ (Patau Syndrome)

A rare genetic disorder caused by an extra copy of chromosome $13$, leading to severe physical and intellectual abnormalities and a high risk of early mortality.

Trisomy $18$ (Edward Syndrome)

A condition caused by an extra copy of chromosome $18$, resulting in three copies of chromosome $18$ in body cells instead of two.

Trisomy $21$ (Down Syndrome)

A genetic condition caused by an extra copy of chromosome $21$.

Trisomy X (XXX)

A genetic condition where a female is born with an extra X chromosome.

Klinefelter Syndrome

A common genetic condition in which males have an additional X chromosome.

Jacob's Syndrome

A condition in which males have an additional Y chromosome in their genetic code.

Chromosomal Deletion Syndrome

A genetic disorder caused by the loss of a segment of DNA from a chromosome.

Cri-Du-Chat Syndrome (5-P Minus Syndrome)

A rare chromosomal disorder caused by a deletion of genetic material on part of chromosome $5$.

Wolf-Hirschhorn Syndrome (4-P Minus Syndrome)

A rare genetic disorder caused by a microdeletion on the short arm (p) of chromosome $4$.