The Cell Cycle and Mitosis

Chapter 6 Flashcards :)

Cytokinesis

The division of the cytoplasm to form two separate daughter cells during cell division.

Prokaryotic Chromosome

A circular DNA molecule containing the genetic material of a prokaryotic cell.

Eukaryotic Chromosome

A linear DNA structure packaged with proteins located in the nucleus of a eukaryotic cell.

Chromatin

The uncoiled complex of DNA and proteins forming eukaryotic chromosomes.

Chromatid

One copy of a newly replicated chromosome that is typically joined to another copy at the centromere.

Genome

The complete genetic material or DNA complement of an organism or cell.

Gene

A distinct sequence of DNA that encodes functional products and acts as the basic unit of heredity.

Allele

An alternative version of a specific gene.

Locus

The specific physical location or site of a gene on a chromosome.

Homozygote

An organism or individual that possesses two identical alleles for a particular gene.

Heterozygote

An organism or individual that possesses two different alleles for a particular gene.

Somatic Cell

Any biological cell forming the body of a multicellular organism, other than a gamete or reproductive cell.

Gamete

A mature haploid reproductive cell, such as an egg or sperm, that unites with another in sexual reproduction.

Haploid

A cell or organism having a single set of unpaired chromosomes ($n$).

Diploid

A cell or organism containing two complete sets of chromosomes ($2n$), one from each parent.

Centromere

The specialized region of a chromosome where sister chromatids are most closely attached and where spindle fibers attach during division.

Telomere

The repetitive nucleotide sequence at each end of a linear eukaryotic chromosome that protects chromosome ends from deterioration.

Homologous Chromosomal Pair

A pair of chromosomes that share the same size, centromere position, and genes, but may carry different alleles, meaning they are not identical.

Sister Chromatids

Two identical copies of a single replicated chromosome that are joined together at the centromere.

Non-sister Chromatids

Chromatids from different chromosomes of a homologous pair that carry the same genes but are not identical copies.

Mitotic Spindle

An apparatus composed of microtubules and associated proteins that orchestrates chromosome movement during mitosis.

Centrosome

A microtubule-organizing center in eukaryotic cells that functions throughout the cell cycle to organize the mitotic spindle.

Binary Fission

The asexual process of cell division utilized by prokaryotes to replicate and divide into two cells.

Cell Cycle Control System

A cyclically operating set of molecules in eukaryotic cells that triggers and coordinates key events of the cell cycle based on checkpoint go-ahead signals.

Density-dependent Growth Inhibition

A phenomenon in normal animal cells causing them to stop dividing when they come into contact with one another.

Benign Tumor

A mass of abnormal cells that remains localized at its original site and does not spread to surrounding tissue.

Malignant Tumor

A cancerous mass of cells that invades surrounding tissues and can metastasize to other parts of the body due to loss of cell cycle regulation.

Transformation

The cellular process that converts a normal cell into a cancerous cell, resulting in unregulated proliferation.

Mitosis

The process of cell division where a single cell divides to produce two identical daughter cells, each containing the same number of chromosomes as the parent cell.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes, the nucleolus disappears, and the mitotic spindle begins to form.

Metaphase

The second stage of mitosis where chromosomes align at the cell's equatorial plane, and spindle fibers attach to the centromeres of the chromosomes.

Anaphase

The third stage of mitosis where sister chromatids separate and are pulled towards opposite poles of the cell by the spindle fibers.

Telophase

The final stage of mitosis where the chromatids reach the poles, the nuclear envelope re-forms around each set of chromosomes, and the chromosomes begin to decondense back into chromatin.

Interphase

The phase of the cell cycle where the cell prepares for mitosis, including DNA replication and the increase of cell size and organelles.

G₁

The first phase of interphase where the cell grows and synthesizes proteins required for DNA replication. It's a period of intense metabolic activity and preparation for the next phase.

$S$ Phase

The synthesis phase of interphase during which DNA replication occurs.

G₂

The second phase of interphase that follows S phase, during which the cell continues to grow and prepares for mitosis by synthesizing proteins and organelles.