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The assembly of microtubules is responsible for the movement of chromosomes during anaphase is called what?
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∙ 11y ago
chromatin
Wiki User
∙ 11y ago
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What is consist of hollow tubes which provide support for the cell?
Microtubules are rigid hollow rods which help support and shape a cell. They undergo continual assembly and disassembly within the cell.
How does the structure of microtubules allow them to apparently move from one location of a cell to another?
Microtubules are made of a dimer protein called tubulin. They grow in length by adding tubulin dimers, but they can also be disassembled. This process of assembly and disassembly makes the microtubule seem to move from one location of the cell to another.
What assembly and disassembly is responsible for the cytoplasmic movement that allow cells such amoebas to crawl along surfaces?
Microfilament
What functions do centrioles perform an animal cell mitosis?
Centrioles are found in animal cells, and they help to organize the assembly of microtubules during cell division. During the interphase stage of mitosis, a pair of centrioles replicates into two pairs of centrioles.
Is mitochondria responsible for protein assembly?
Basic role of mitochondria is respiration not protein synthesis . Ribosomes synthesize proteins .
What is a function of those spindle microtubules that do not attach to kinetochores?
microtubules attached to a chromosome Wiki Answers respondents need to start answering questions with a greater sense of purpose. People do not ask questions to receive a terse, slightly correct answer. They want a valid answer to a valid question. As per this one, kinetochore microtubules are NOT just microtubules attached to a chromosome. They are microtubules attached to kinetochores on the centromeres of chromatids. Two chromatids make up a "chromosome" and each chromatid has a centromere with a kinetochore on it. When microtubules from the spindle pole attach to the kinetochores on each side of the "chromosome" the two kinetochore microtubules (from opposite poles of the cell) successfully pull the "chromosome" apart and provide each new developing daughter cell nucleus with a chromatid from that chromatid pair.
The cancer drug vinblastine interferes with synthesis of microtubules and in mitosis this would interfere with what?
Spindle formation or assembly.
When are centioles used?
Centrioles are used when cells divide. They are found in animal cells and organize the assembly of microtubules during division.
In animal cells taxol an anti-cancer drug binds to microtubules and accelerates their assembly stopping mitosis so what in the cell cycle does taxol affect?
Taxol binds to ß-tubulin to promote microtubule assembly and it stabilises the microtubules and messes up the equilibrium between tubulin and microtubule. A cell with stable microtubules proceeds to programmed cell death without dividing. Nathalie Narraidoo University of Nottingham
What is consist of hollow tubes which provide support for the cell?
Microtubules are rigid hollow rods which help support and shape a cell. They undergo continual assembly and disassembly within the cell.
What do a assembly line do?
The assembly-line manager or supervisor is only responsible for the line that he or she oversees
Why does taxus brevifolius have potential as an anticancer drug?
Because Taxol can induce the assembly of tubulin into microtubules and stabalizes them to the extent that mitosis of cancer cells is disrupted.
Who was responsible for the first assembley line?
Ransome E. Old was responsible for the first assembly line, but Henry Ford made the first MOVING assembly line.
What does a assembly-line manager do?
The assembly-line manager or supervisor is only responsible for the line that he or she oversees
How does the structure of microtubules allow them to apparently move from one location of a cell to another?
Microtubules are made of a dimer protein called tubulin. They grow in length by adding tubulin dimers, but they can also be disassembled. This process of assembly and disassembly makes the microtubule seem to move from one location of the cell to another.
What is the process where one cell divides into two identical ones?
The process is knwon as mitosis and it has following stages Phases of cell cycle and mitosis InterphaseThe mitotic phase is a relatively short period of the cell cycle. It alternates with the much longer interphase, where the cell prepares itself for cell division. Interphase is therefore not part of mitosis. Interphase is divided into three phases, G1 (first gap), S (synthesis), and G2 (second gap). During all three phases, the cell grows by producing proteins and cytoplasmic organelles. However, chromosomes are replicated only during the S phase. Thus, a cell grows (G1), continues to grow as it duplicates its chromosomes (S), grows more and prepares for mitosis (G2), and finally divides (M) before restarting the cycle. Preprophase In plant cells only, prophase is preceded by a pre-prophase stage. In highly vacuolated plant cells, the nucleus has to migrate into the center of the cell before mitosis can begin. This is achieved through the formation of a phragmosome, a transverse sheet of cytoplasm that bisects the cell along the future plane of cell division. In addition to phragmosome formation, preprophase is characterized by the formation of a ring of microtubules and actin filaments (called preprophase band) underneath the plasma membrane around the equatorial plane of the future mitotic spindle. This band marks the position where the cell will eventually divide. The cells of higher plants (such as the flowering plants) lack centrioles: with microtubules forming a spindle on the surface of the nucleus and then being organized into a spindle by the chromosomes themselves, after the nuclear membrane breaks down. The preprophase band disappears during nuclear envelope disassembly and spindle formation in prometaphase. Prophase Normally, the genetic material in the nucleus is in a loosely bundled coil called chromatin. At the onset of prophase, chromatin condenses together into a highly ordered structure called a chromosome. Since the genetic material has already been duplicated earlier in S phase, the replicated chromosomes have two sister chromatids, bound together at the centromere by the cohesion complex. Chromosomes are visible at high magnification through a light microscope. Close to the nucleus are structures called centrosomes, which are made of a pair of centrioles. The centrosome is the coordinating center for the cell's microtubules. A cell inherits a single centrosome at cell division, which replicates before a new mitosis begins, giving a pair of centrosomes. The two centrosomes nucleate microtubules (which may be thought of as cellular ropes or poles) to form the spindle by polymerizing soluble tubulin. Molecular motor proteins then push the centrosomes along these microtubules to opposite side of the cell. Although centrosomes help organize microtubule assembly, they are not essential for the formation of the spindle, since they are absent from plants, and centrosomes are not always used in meiosis. PrometaphaseThe nuclear envelope disassembles and microtubules invade the nuclear space. This is called open mitosis, and it occurs in most multicellular organisms. Fungi and some protists, such as algae or trichomonads, undergo a variation called closed mitosis where the spindle forms inside the nucleus or its microtubules are able to penetrate an intact nuclear envelope. Each chromosome forms two kinetochores at the centromere, one attached at each chromatid. A kinetochore is a complex protein structure that is analogous to a ring for the microtubule hook; it is the point where microtubules attach themselves to the chromosome. Although the kinetochore structure and function are not fully understood, it is known that it contains some form of molecular motor. When a microtubule connects with the kinetochore, the motor activates, using energy from ATP to "crawl" up the tube toward the originating centrosome. This motor activity, coupled with polymerisation and depolymerisation of microtubules, provides the pulling force necessary to later separate the chromosome's two chromatids. When the spindle grows to sufficient length, kinetochore microtubules begin searching for kinetochores to attach to. A number of nonkinetochore microtubules find and interact with corresponding nonkinetochore microtubules from the opposite centrosome to form the mitotic spindle. Prometaphase is sometimes considered part of prophase. MetaphaseAs microtubules find and attach to kinetochores in prometaphase, the centromeres of the chromosomes convene along the metaphase plate or equatorial plane, an imaginary line that is equidistant from the two centrosome poles. This even alignment is due to the counterbalance of the pulling powers generated by the opposing kinetochores, analogous to a tug-of-war between people of equal strength. In certain types of cells, chromosomes do not line up at the metaphase plate and instead move back and forth between the poles randomly, only roughly lining up along the midline. Metaphase comes from the Greek μετα meaning "after." Because proper chromosome separation requires that every kinetochore be attached to a bundle of microtubules (spindle fibres), it is thought that unattached kinetochores generate a signal to prevent premature progression to anaphase without all chromosomes being aligned. The signal creates the mitotic spindle checkpoint. AnaphaseWhen every kinetochore is attached to a cluster of microtubules and the chromosomes have lined up along the metaphase plate, the cell proceeds to anaphase (from the Greek ανα meaning "up," "against," "back," or "re-"). Two events then occur; First, the proteins that bind sister chromatids together are cleaved, allowing them to separate. These sister chromatids, which have now become distinct sister chromosomes, are pulled apart by shortening kinetochore microtubules and move toward the respective centrosomes to which they are attached. Next, the nonkinetochore microtubules elongate, pushing the centrosomes (and the set of chromosomes to which they are attached) apart to opposite ends of the cell. The force that causes the centrosomes to move towards the ends of the cell is still unknown, although there is a theory that suggests that the rapid assembly and breakdown of microtubules may cause this movement. These two stages are sometimes called early and late anaphase. Early anaphase is usually defined as the separation of the sister chromatids, while late anaphase is the elongation of the microtubules and the microtubules being pulled farther apart. At the end of anaphase, the cell has succeeded in separating identical copies of the genetic material into two distinct populations. TelophaseTelophase (from the Greek τελος meaning "end") is a reversal of prophase and prometaphase events. It "cleans up" the after effects of mitosis. At telophase, the nonkinetochore microtubules continue to lengthen, elongating the cell even more. Corresponding sister chromosomes attach at opposite ends of the cell. A new nuclear envelope, using fragments of the parent cell's nuclear membrane, forms around each set of separated sister chromosomes. Both sets of chromosomes, now surrounded by new nuclei, unfold back into chromatin. Mitosis is complete, but cell division is not yet complete. CytokinesisCytokinesis is often mistakenly thought to be the final part of telophase; however, cytokinesis is a separate process that begins at the same time as telophase. Cytokinesis is technically not even a phase of mitosis, but rather a separate process, necessary for completing cell division. In animal cells, a cleavage furrow (pinch) containing a contractile ring develops where the metaphase plate used to be, pinching off the separated nuclei. In both animal and plant cells, cell division is also driven by vesicles derived from the Golgi apparatus, which move along microtubules to the middle of the cell. In plants this structure coalesces into a cell plate at the center of the phragmoplast and develops into a cell wall, separating the two nuclei. The phragmoplast is a microtubule structure typical for higher plants, whereas some green algae use a phycoplast microtubule array during cytokinesis. Each daughter cell has a complete copy of the genome of its parent cell. The end of cytokinesis marks the end of the M-phase.
Mitosis could not proceed if a mutation interrupted the assembly of?
The spindle fibers, which are essential to the movement of chromosomes.
