Campbell Biology 10Th - Chap 12 Mitosis

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cell cycle

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The cell cycle or cell-division cycle is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells.

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genome

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Genetic material of an organism. It consists of DNA (or RNA in RNA viruses). The genome includes both the genes and the non-coding sequences of the DNA/RNA.

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chromosomes

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A Cellular structure consisting of one DNA molecule and associated protein molecules. In some contexts such as genome sequencing, the term may refer to the DNA alone. A eukaryotic cell typically has multiple, linear chromosomes which are located in the nucleus. A prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is not enclosed by a membrane

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chromatin

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The complex of DNA and proteins that makes up eukaryotic chromosomes. Chromosome subunits. When the cell is not dividing chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope

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chromatin

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A chromatid (Greek khrōmat- 'color' + -id) is one copy of a newly copied chromosome which is still joined to the other copy by a single centromere.

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Euchromatin

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is a lightly packed form of chromatin (DNA, RNA and protein) that is enriched in genes, and is often (but not always) under active transcription.

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Heterochromatin

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Heterochromatin is a tightly packed form of DNA, which comes in multiple varieties.

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differentiate between chromosome, chromatin, and chromatid

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Chromosome is the genetic material of an organism. Consist of gene and non-coding sequences; Chromatid is the newly formed chromosome still connected with the other copy of chromatid by a single centromere ; Chromatin is the subunit of chromosome. It is a complex of DNA and proteins

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somatic cells

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A somatic (Greek: σὠμα/soma = body) or vegetal cell is any biological cell forming the body of an organism

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sister chromatids

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A sister chromatid refers to either of the two identical copies (chromatids) formed by the replication of a single chromosome, with both copies joined together by a common centromere.

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cohesin

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Cohesin is a protein complex that regulates the separation of sister chromatids during cell division, either mitosis or meiosis.

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sister chromatid cohesion

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Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles.

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centromere

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The centromere is the part of a chromosome that links sister chromatids. During mitosis, spindle fibers attach to the centromere via the kinetochore.[1] Centromeres were first defined as genetic loci that direct the behavior of chromosomes.

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cytokinesis

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Cytokinesis (from the Greek κύτος, "container" and κίνησις, "motion") is the process during cell division in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells.

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meiosis

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a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell

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mitosis

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a process of nuclear division in eukaryotic cells convnetionally divided into 5 stages: prophase, prometaphase, metaphse, anaphase, and telophase. Mitosis conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei

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M phase

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the phase of the cell cycle that includes mitosis and cytokinesis

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interphase

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the period in the cell cycle when the cell is not dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase often accounts for about 90% of the cell cycle. Interphase include G1, S, G2 phases.

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g1 phase

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the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins

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s

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chromosomes are copied in s phase (DNA synthesis)

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g2 phase

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the second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs

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five stages of mitosis

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prophase, prometaphse, metaphse, anaphase, and telophase

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prophase

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1. chromatin fibers tightly coiled. 2. identical sister chromatids 3. mitotic spindle begins to form. radial arrays of shorter microtubules extend from centrosomes are called asters

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prometaphase

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1. nuclear envolope fragments. 2. microtubules invade nuclear area 3. chromosomes more condensed 4. each two chromatids of chromosomes has kinetochore 5. some microtubules attch to kinetochores forming kinetochore microtubules 6.

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metaphase

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1. centrosome at opposite poles of cell. 2. chromosomes lining up metaphse plate 3. each chromosome with sister chromatids attached to kinetochore microtubules from opposite pols

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anaphase

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1. shortest stage of mitosis. 2. cohesin proteins cleaved, two sister chromatids to part. 3. two daughter chromosomes move towards opposite ends of cell 4. cell elongates 5. two ends of the cell have complete and equivalent chromosome sets

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telophase

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1. daughter nuclei form 2. nuclear envelopes arise from fragments 3. nucleoli reappear 4. chromosome less condensed 5. form two identical nuclei

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mitotic spindle

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During mitosis, the spindle fibers are called the mitotic spindle. Spindle fibers are microtubules originating from attaching to the kinetochores and g to the opposite sites of the cells

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metaphase plate

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a plane that is equidistant to the two poles of the spindle. It is an imaginary plane where the microtubule-attached kinetochores line up in metaphase and ready to enter anaphase

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centrosome

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an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell-cycle progression.

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centromere

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the part of a chromosome that links sister chromatids. it is also the site of assembly of kinetochores

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microtubule-organizer centre

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The microtubule-organizing center (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. MTOCs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division. The MTOC is a major site of microtubule nucleation and can be visualized in cells by immunohistochemical detection of γ-tubulin. The morphological characteristics of MTOCs vary between the different phyla and kingdoms.[1] In animals, the two most important types of MTOCs are the basal bodies associated with cilia and the centrosome associated with spindle formation.

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aster

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An aster is a cellular structure shaped like a star, formed around each centrosome during mitosis in an animal cell.[1] Astral rays, composed of microtubules, radiate from the centrosphere and look like a cloud. It is one of the variants of microtubules like kinetochore- and interpolar microtubules.

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kinetochore

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The kinetochore /kɪˈnɛtəkɔər/ is the protein structure on chromatids where the spindle fibers attach during cell division to pull sister chromatids apart.

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separase

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Separase, also known as separin, is a cysteine protease responsible for triggering anaphase by hydrolysing cohesin, which is the protein responsible for binding sister chromatids during the early stage of anaphase.[1] In humans, separin is encoded by the ESPL1 gene.[2]

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cleavage furrow

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cleavage furrow is the indentation of the cell's surface that begins the progression of cleavage, by which animal and some algal cells undergo cytokinesis, the final splitting of the membrane, in the process of cell division.

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shortening of kinetochore

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the microtubules at the kinetochore are shortened as they depolymerizes at the inetochore end, releasing tubulin subunits.

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origin of replication

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the site on the chromosome at which DNA of the bacterial chromosome begins to replicate. One origin moves rapidly toward the opposite end of the cell as the chromosome continue to replicate

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checkpoint

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a control point in the clel cycle where stop and go-ahead signals can regulate the cycle. There are three important checkpoints found in G1, G2, and M phases.

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three checkpoints

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Found in G1, G2, M phases

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cyclin

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a protein that cyclically fluctuate in concentration in the cell. It attaches to cyclin-dependent kinases, whose activity also rise and fall depending on its cyclin partner

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Cdks

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Cyclin-dependent kinase

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MPF

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maturation-promoting factor

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G0 phase

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during cell cycle, if the cell does not receive a go-ahead signal at the checkpoints, then it may exit the cycle, and enter a nondividing state, the G0 phase. Most cells of the human body are actually in the G0 phase

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growth factor

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a protein release by certain cells that stimulates other cells to divide

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PDGF

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platelet-derived growth factor, made by blood cell fragments called platelets. It is required for the division of cultured fibroblasts, a type of connective tissue cell. Binding of PDGF molecules to PDGF receptors on fibroblasts plasma membrane would trigger a singal transduction pathway that allows the cells to pass the G1 chekc point and divide.

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density-dependent inhibition

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a phenomenon in which crowded cells stop dividing

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anchorage dependence

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The characteristics of animal cells that when dividing, they must be attached to a substratum, such as the inside of a culture flask or the extracellular matrix of a tissue.

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transformation

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cells in culture that acquire the ability to divide indefiintely are said to have undergone transformation, the process that causes them to behave like cancer cells.

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metastasis

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the spread of cancer cells to locations distant from their original site

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malignant tumor

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a mass of abnormal cells within otherwise normal tissue. Malignant tumor includes cells whose genetic and cellular changes enable them to spread to new tissues and impair the f unctions of one or more organs. These cells are also considered transformed cells

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benign tumor

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abnormal cells growing in normal tissues. These cells do not have enough genetic or cellular changes to survive at another site.

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cytology

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Cytology is that branch of life science that deals with the study of cells in terms of structure, function and chemistry.

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sex chromosome

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An allosome (also referred to as a sex chromosome, heterotypical chromosome, heterochromosome,[1][2] or idiochromosome[3]) is a chromosome that differs from an ordinary autosome in form, size, and behavior. The human sex chromosomes, a typical pair of mammal allosomes, determine the sex of an individual created in sexual reproduction. In humans, each cell nucleus contains 23 pairs of chromosomes a total of 46 chromosomes. The first 22 pairs are called autosomes which look exactly the same in both males and females. The 23rd pair of chromosomes is called an allosome. These sex chromosomes differ between males and females. Females have two copies of the X chromosome, while males have one X chromosome and one Y chromosome. The X chromosome is always present as the 23rd chromosome in the ovum, while either X or Y chromosomes can be present in an individual sperm.[4]

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autosome

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Chromosomes other than sex chromosome. Can be found in both males and females in which the autosomes look exactly the same

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motor proteins

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myosin (actin motors), kinesin (microtubule motors), dynein (microtubule motors)

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kinesin

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are a group of related motor proteins that use a microtubule track in antegrade movement. They are vital to spindle formation in mitotic and meiotic and chromosomes separation during cell division and are also responsible for shuttling mitochondria, Golgi bodies, and vesicles within eukaryotic cells

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myosin

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Myosin II are also vital in the process of cell division. For example, non-muscle myosin II bipolar thick filaments provide the force of contraction needed to divide cell into two daughter cells during cytokinesis.In addition to myosin II, many other myosin types are responsible for variety of movement of non-muscle cells. For example, myosin I involved in intracellular organization and the protrusion of actin-rich structures at the cell surface. Myosin V is involved in vesicle and organelle transport.[2] Myosin XI are involved in cytoplasmic streaming, wherein movement along microfilament networks in the cell allows organelles and cytoplasm to stream in a particular direction.

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dynein

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are microtubule motors capable of a retrograde sliding movement.