Mitosis and Meosis terms

Anaphase

The stage of mitosis or meiosis where sister chromatids (mitosis) or homologous chromosomes (meiosis I) are pulled apart to opposite poles of the cell.

Anaphase-Promoting Complex (APC)

A protein complex that triggers the separation of sister chromatids by marking key proteins for degradation during anaphase.

Aster

A radial array of microtubules that forms around each centrosome during mitosis in animal cells, helping position the spindle apparatus.

Binary Fission

A form of asexual reproduction in prokaryotes where the cell divides into two identical daughter cells.

Cancer

A disease characterized by uncontrolled cell division due to the failure of normal cell cycle regulation.

Cell Cycle

The series of events that take place in a cell, leading to its growth, DNA replication, and division into two daughter cells.

Cell Plate

A structure formed during cytokinesis in plant cells that develops into a new cell wall, dividing the two daughter cells.

Centromere

The region of a chromosome where sister chromatids are joined and where the kinetochore attaches during cell division.

Chromatin

The complex of DNA and proteins that makes up chromosomes, typically uncondensed during interphase.

Cleavage Furrow

The indentation of the cell's surface during cytokinesis in animal cells, which eventually pinches the cell into two.

Condensin

A protein complex that helps condense chromosomes into their compact, X-shaped form during mitosis and meiosis.

Cohesin

A protein complex that holds sister chromatids together until they are separated during anaphase.

Cyclins

Regulatory proteins that control the progression of the cell cycle by activating cyclin-dependent kinases (Cdks).

Cyclin-Dependent Kinase (Cdk)

Enzymes that, when combined with cyclins, phosphorylate target proteins to regulate the cell cycle.

Cytokinesis

The division of the cytoplasm following mitosis or meiosis, resulting in two daughter cells.

Diploid

A cell with two complete sets of chromosomes, one from each parent (2n), typical of somatic cells.

Euchromatin

A loosely packed form of chromatin that is transcriptionally active, allowing gene expression.

FtsZ Protein

A protein involved in bacterial cell division, forming a ring at the site of division and assisting in septation.

G0 Phase

A resting phase of the cell cycle where the cell is not actively preparing to divide and performs its regular functions.

G1 (Gap 1) Phase

The first growth phase of the cell cycle, during which the cell grows and performs its normal functions before DNA replication.

G1/S Checkpoint

A checkpoint in the cell cycle that assesses whether the cell has sufficient size and energy to proceed to DNA replication in the S phase.

G2 (Gap 2) Phase

The second growth phase of the cell cycle, after DNA replication, where the cell prepares for mitosis.

G2/M Checkpoint

A checkpoint in the cell cycle that ensures the cell is ready to enter mitosis, checking for proper DNA replication and damage repair.

Haploid

A cell with only one set of chromosomes (n), typically found in gametes like sperm and egg cells.

Heterochromatin

A tightly packed form of chromatin that is transcriptionally inactive, typically located at the chromosome’s centromeres and telomeres.

Histone Proteins

Positively charged proteins around which DNA winds to form nucleosomes, helping to package DNA into chromatin.

Homologous Chromosomes

Pairs of chromosomes, one from each parent, that are similar in structure and carry genes for the same traits.

Homologue

One of a pair of homologous chromosomes.

Interphase

The phase of the cell cycle in which the cell grows, replicates its DNA, and prepares for mitosis, encompassing G1, S, and G2 phases.

Karyotype

The number and appearance of chromosomes in the nucleus of a cell, typically used for chromosomal analysis.

Kinetochore

A protein complex located at the centromere of a chromosome where spindle fibers attach during mitosis and meiosis.

M-Phase Promoting Factor (MPF)

A complex of cyclin and Cdk that triggers the cell's entry into mitosis from the G2 phase.

Maturation-Promoting Factor

Another term for M-phase promoting factor (MPF), which initiates mitosis by phosphorylating key proteins.

Metaphase

The phase of mitosis or meiosis where chromosomes line up along the metaphase plate in preparation for separation.

Mitosis

• Definition: A process of cell division where a single cell divides to produce two genetically identical daughter cells.

Nucleosome

• Definition: The basic unit of chromatin, consisting of DNA wound around a core of histone proteins.

Oncogenes

• Definition: Mutated proto-oncogenes that promote uncontrolled cell growth and can lead to cancer.

Platelet-Derived Growth Factor (PDGF)

• Definition: A signaling molecule that stimulates cell division and healing, particularly in wound repair.

Prometaphase

• Definition: The phase of mitosis where the nuclear envelope breaks down and spindle fibers attach to kinetochores.

Prophase

• Definition: The first phase of mitosis where chromosomes condense, and the spindle apparatus begins to form.

Proto-Oncogenes

• Definition: Normal genes that promote cell division; when mutated, they can become oncogenes and lead to cancer.

Ras Protein

• Definition: A protein involved in cell signaling pathways that regulate cell growth; mutations in Ras can lead to cancer.

Septation

• Definition: The process in which a septum forms between two dividing bacterial cells, leading to their separation.

Septum

• Definition: A dividing wall or membrane that separates two newly forming bacterial cells after division.

Sister Chromatids

These are identical copies of a chromosome, formed during DNA replication. They are connected at a region called the centromere and separate during cell division, ensuring that each new cell receives an identical set of chromosomes.

S (Synthesis) Phase

• Definition: The phase of the cell cycle where DNA is replicated, resulting in two sister chromatids for each chromosome.

Spindle Apparatus

• Definition: A structure made of microtubules that helps separate chromosomes during mitosis and meiosis.

Telophase

• Definition: The final phase of mitosis where chromosomes reach opposite poles, decondense, and are surrounded by newly reformed nuclear envelopes.

Topologically Associated Domains (TADs)

• Definition: Regions of chromatin that interact more frequently with each other than with other regions, helping regulate gene expression.

Tumor Suppressor Genes

• Definition: Genes that help prevent uncontrolled cell growth by regulating the cell cycle; mutations can lead to cancer.

P53 Protein

• Definition: A tumor suppressor protein that regulates the cell cycle and triggers apoptosis if DNA damage is detected.