Cell cycle

thumb|upright=1.5|Mitosis in the animal cell cycle (phases ordered counter-clockwise).

thumb|300x300px|In meiosis, the chromosomes duplicate (during [[interphase) and homologous chromosomes exchange genetic information (chromosomal crossover) during the first division, called meiosis I. The daughter cells divide again in meiosis II, splitting up sister chromatids to form haploid gametes. Two gametes fuse during fertilization, forming a diploid cell (zygote) with a complete set of paired chromosomes.]]

process resulting in division and partitioning of components of a cell to form more cells

progression of biochemical and morphological phases and events that occur in a cell during successive cell replication or nuclear replication events

thumb|upright=1.35|Diagram of cytokinesis

thumb|upright=1.35|Prophase is the first step of cell division in mitosis. As it occurs after G2 of interphase, DNA has been already replicated when prophase begins. thumb|right|200px|Fluorescence microscope image of two mouse cell nuclei in prophase (scale bar is 5 μm).

thumb|upright=1.35|The mitotic spindle checkpoint verifies that all the chromosomes are aligned properly on the metaphase plate and prevents premature entry into anaphase.

alt=A detailed diagram of telophase|thumb|upright=1.35|Diagram of telophase

Amitosis, also known as karyostenosis, direct cell division, or binary fission, is a form of asexual cell division that occurs in most prokaryotes. It differs from other forms of cell division (e.g., mitosis, meiosis) as it does not involve the mitotic apparatus (spindle formation) or the condensation of chromatin into chromosomes prior to cellular division.

biological process

connection formed between chromatids, visible during meiosis, thought to be the point of the interchange involved in crossing-over

thumb|Tertiary structure of human cyclin A (lacking the amino-terminal 170 amino acids), showing the central core of two five-helix bundles, with additional helices at the amino terminus (black) and carboxyl terminus (grey). The yellow region in helix 1 is the MRAIL sequence or hydrophobic patch, which contributes to the recognition of some substrates. (PDB 1fin)

cell cycle phase, following G1, during which DNA synthesis takes place

cell cycle 'gap' phase

process that controls cell cycle progression by monitoring the integrity of specific events

process in which a cell irreversibly increases in size over time by accretion and biosynthetic production of matter similar to that already present

cell cycle gap phase - interval between the completion of DNA synthesis and the beginning of DNA segregation

thumb|300px|Phragmoplast and cell plate formation in a plant cell during cytokinesis. Left side: Phragmoplast forms and cell plate starts to assemble in the center of the cell. Towards the right: Phragmoplast enlarges in a donut-shape towards the outside of the cell, leaving behind mature cell plate in the center. The cell plate will transform into the new cell wall once cytokinesis is complete.

Quiescent stage of the cell cycle in which the cell does not divide

450px|thumb|Figure 1. An interphase nucleus (left) and a set of mitotic chromosomes (right) from human tissue culture cells. Bar, 10 μm. Condensins are large protein complexes that play a central role in chromosome condensation and segregation during mitosis and meiosis (Figure 1). Their subunits were originally identified as major components of mitotic chromosomes assembled in Xenopus egg extracts.

ubiquitin ligase complex that degrades mitotic cyclins and anaphase inhibitory protein, thereby triggering sister chromatid separation and exit from mitosis. Substrate recognition by APC occurs through degradation signals, the most common of which

E2F is a group of genes that encodes a family of transcription factors (TF) in higher eukaryotes. Three of them are activators: E2F1, 2 and E2F3a. Six others act as repressors: E2F3b, E2F4-8. All of them are involved in the cell cycle regulation and synthesis of DNA in mammalian cells. E2Fs as TFs bind to the TTTCCCGC (or slight variations of this sequence) consensus binding site in the target promoter sequence.

mammalian protein found in Homo sapiens

biological factor

process in which genetic material, in the form of chromosomes, is organized into specific structures

InterPro Family

mammalian protein found in Homo sapiens

pair of homologous chromosomes during meiotic synapsis

Endoreduplication (also referred to as endoreplication or endocycling) is replication of the nuclear genome in the absence of mitosis, which leads to elevated nuclear gene content and polyploidy. Endoreduplication can be understood simply as a variant form of the mitotic cell cycle (G1-S-G2-M) in which mitosis is circumvented entirely, due to modulation of cyclin-dependent kinase (CDK) activity. Examples of endoreduplication characterised in arthropod, mammalian, and plant species suggest that it is a universal developmental mechanism responsible for the differentiation and morphogenesis of ce

thumb|Phragmosome formation in a highly vacuolated plant cell. From top to bottom: 1) Interphase cell with large central vacuole. 2) Cytoplasmic strands starting to penetrate vacuole. 3) Nucleus migration into center and formation of the phragmosome. 4) Phragmosome formation completed and formation of preprophase band marking future cell division plane.

nascent cell membrane and cell wall structure that forms between two daughter nuclei near the center of a dividing plant cell

Cdc25 is a dual-specificity phosphatase first isolated from the yeast Schizosaccharomyces pombe as a cell cycle defective mutant. As with other cell cycle proteins or genes such as Cdc2 and Cdc4, the "cdc" in its name refers to "cell division cycle". Dual-specificity phosphatases are considered a sub-class of protein tyrosine phosphatases. By removing inhibitory phosphate residues from target cyclin-dependent kinases (Cdks), Cdc25 proteins control entry into and progression through various phases of the cell cycle, including mitosis and S ("Synthesis") phase.

protein-coding gene in the species Homo sapiens

Wee1 is a nuclear kinase belonging to the Ser/Thr family of protein kinases in the fission yeast Schizosaccharomyces pombe (S. pombe). Wee1 has a molecular mass of 96 kDa and is a key regulator of cell cycle progression.

protein-coding gene in the species Homo sapiens

cellular structure shaped like a star

InterPro Family

protein-coding gene in the species Homo sapiens

350px|right|thumb|Microtubule dynamics during preprophase and prophase in plant cell mitosis, modified from Donukshe et al. The images follow a Tobacco BY-2 cells|tobacco BY-2 cell through the first stages of mitosis (c. 12 minutes). The growing ends of microtubules are shown in green (labeled with [[green fluorescent protein fused to the microtubule plus end binding protein EB1 of Arabidopsis thaliana). N = Nucleus, V = Vacuole, PPB = Preprophase band, MTN = Microtubule nucleation starts at the nuclear envelope, NEB = Nuclear envelope breakdown at the onset of prometaphase. Also see the movie

dense band of microtubules, 1-3 pm wide, that appears just beneath the cell membrane before the start of cell division in the cells of higher plants. It precedes the onset of prophase and then disappears as mitosis begins, yet it somehow determines

density-dependent processes occur when population growth rates are regulated by the density of a population

thumb|Schematic representation of types of cytokinesis in the green algae: 1) Phycoplast formation with cleavage furrow (e.g. Chlamydomonas); 2) Cleavage furrow and persistent telophase spindle (e.g. Klebsormidium); 3) Phycoplast and cell plate formation (e.g. Fritschiella); 4) Persistent telophase spindle/phragmoplast with cell plate formation (e.g. [[Coleochaete)]]

protein-coding gene in the species Homo sapiens

InterPro Family

Septins are a group of GTP-binding proteins expressed in all eukaryotic cells except plants. Different septins form protein complexes with each other. These complexes can further assemble into filaments, rings and gauzes. Assembled as such, septins function in cells by localizing other proteins, either by providing a scaffold to which proteins can attach, or by forming a barrier preventing the diffusion of molecules from one compartment of the cell to another, or in the cell cortex as a barrier to the diffusion of membrane-bound proteins.

protein family

protein-coding gene in the species Homo sapiens

protein-coding gene in the species Homo sapiens

protein-coding gene in the species Homo sapiens

undesirable and possibly fatal occurrence in eukaryotic cells in which the genome is replicated more than once per cell cycle

protein-coding gene in the species Homo sapiens