During the last phase of mitosis, telophase, the two sets of chromosomes reach the opposite poles of the cell. After the M phase is the separation of the cytoplasm, known as cytokinesis, which results in two distinct daughter cells.
In the next phase, metaphase, the chromosomes line up along the metaphase plate. In which phase of mitosis does a cell utilize a specific control mechanism to verify its readiness for DNA synthesis? The G1 phase is the first phase within interphase.
It can more easily be remembered as the "first growth" phase. During this period the cell increases its supply of proteins while also increasing the number of organelles such as ribosomes and mitochondria in addition to growing in size. This stage is critical toward making sure that the cell has appropriate resources for DNA synthesis.
After G1, S phase proceeds. In which phase has the cell left the cell cycle and has stopped dividing, in other words, which of the following is the resting phase? G0 phase is a post-mitotic phase. It may be a permanent as often is the case for neurons or semi-permanent for some liver, kidney, and stomach cells phase. Epithelial cells do not enter G0, allowing these cells to continue to divide throughout an organisms life.
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Correct answer: Anaphase. Explanation : The phases of mitosis can be described as follows: During prophase chromatin condenses to form discrete chromosomes. During metaphase microtubules attach to the kinetochores and chromatids begin segregating. During anaphase sister chromatids have been separated and reside at opposite poles of the cell. Cytokinesis the dividing of the cytoplasm into two cells follows telophase.
If the cell were arrested during telophase, distinct chromatids would no longer be visible. Report an Error.
Possible Answers: Anaphase, metaphase, prophase, telophase. Correct answer: Prophase, metaphase, anaphase, telophase. Each sister chromatid develops a protein structure called a kinetochore in the centromeric region. The proteins of the kinetochore attract and bind mitotic spindle microtubules. Kinetochore and Mitotic Spindle : During prometaphase, mitotic spindle microtubules from opposite poles attach to each sister chromatid at the kinetochore.
In anaphase, the connection between the sister chromatids breaks down and the microtubules pull the chromosomes toward opposite poles. The sister chromatids are still tightly attached to each other by cohesin proteins. At this time, the chromosomes are maximally condensed. Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached. The cell becomes visibly elongated oval shaped as the polar microtubules slide against each other at the metaphase plate where they overlap.
The mitotic spindles are depolymerized into tubulin monomers that will be used to assemble cytoskeletal components for each daughter cell.
Nuclear envelopes form around the chromosomes and nucleosomes appear within the nuclear area. Division is not complete until the cell components have been apportioned and completely separated into the two daughter cells.
Although the stages of mitosis are similar for most eukaryotes, the process of cytokinesis is quite different for eukaryotes that have cell walls, such as plant cells.
In cells such as animal cells, which lack cell walls, cytokinesis follows the onset of anaphase. A contractile ring composed of actin filaments forms just inside the plasma membrane at the former metaphase plate. The actin filaments pull the equator of the cell inward, forming a fissure. The furrow deepens as the actin ring contracts; eventually the membrane is cleaved in two.
Cytokinesis : During cytokinesis in animal cells, a ring of actin filaments forms at the metaphase plate. The ring contracts, forming a cleavage furrow, which divides the cell in two. In plant cells, Golgi vesicles coalesce at the former metaphase plate, forming a phragmoplast. A cell plate formed by the fusion of the vesicles of the phragmoplast grows from the center toward the cell walls and the membranes of the vesicles fuse to form a plasma membrane that divides the cell in two.
In plant cells, a new cell wall must form between the daughter cells. During interphase, the Golgi apparatus accumulates enzymes, structural proteins, and glucose molecules prior to breaking into vesicles and dispersing throughout the dividing cell.
During telophase, these Golgi vesicles are transported on microtubules to form a phragmoplast a vesicular structure at the metaphase plate. I nterphase. All rights reserved. P rophase. M etaphase. A naphase. T elophase. The Steps of Mitosis Mitosis is an incredible process with precise steps and regulation. Mitosis: In Summary In prophase, the nucleolus disappears and chromosomes condense and become visible. Practice Quiz Which of the following options shows the correct order of the steps of mitosis?
Show Answer Answer a is correct. If you answered b, you might be having some trouble keeping the beginning steps in order. If you answered c, you might be having some trouble keeping the steps in the second half of mitosis in order. Show Answer The cell shown above is in prophase.
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