number of chromatids per chromosome during cell cycle?
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In G1, there are 46 chromosomes, EACH CONSISTING OF A SINGLE CHROMATID.  You will have two copies of chromosome one (one from mom, the other from dad), two copies of chromosome two, etc.  These pairs are called homologues.  Consequently there are 23 homologous chromosomes in G1 and, again, there is one chromatid per chromosome in this phase.  This gives a total of 46 chromosomes.  You should know that each chromosome is decondensed (not coiled up) at this time. \n\nS phase is the synthesis or replication phase of the cell cycle.  After S phase is complete, the definition of a chromosome changes.  It is now a "replicated chromosome" that consists of 2 chromatids (some texts describe these as "sister chromatids").  Again, the total number of chromosomes is 46; however, because of the definition change of the S-phase chromosome, each chromosome how includes twice as much DNA due to replication.  After S phase there are two chromatids per chromosome.  These chromosomes are decondensed.\n\nIn G2, there are 46 chromosomes:  2 chromatids per chromosome, decondensed, with the chromosomes existing in homologous pairs.\n\nIn prophase of mitosis, the chromosomes condense to facilitate easy separation into the daughter cells.  Here there are still 2 chromatids per chromosome.\n\nIn metaphase, there are STILL 2 chromatids per chromosome, all smartly arranged at the "equator" of the cell, the metaphase plate.\n\nIn anaphase, the replicated chromosomes (i.e., the "sister chromatids") are pulled apart.  At the point that they are separated, the definition of a chromosome changes AGAIN, BACK to a single chromatid.  Each daughter cell will receive 46 of these single chromatids and, therefore, will have 46 chromosomes in 23 homologous pairs.  The chromosomes are still condensed at this point.\n\nIn telophase, the chromosome situation is exactly the same.  23 homologous PAIRS of chromosomes (46 single chromatids).  The difference here is that the chromosomes are now decondensing.\n\nSummary:  the number of chromatids per chromosome\n\nG1-1\nafter S- 2\nG2-2\nprophase-2\nmetaphase-2\nlate anaphase-1\ntelophase-1
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If we were talking about human cells, there are 23 chromosomes in each cell. In mitosis, there are four main steps with another peparation time. The four are Prophase, Metaphase, Anaphase, and Telephase (PMAT). The peparation time before mitosis is called Interphase (not a step of mitosis) where chromosomes duplicate themselves (23 x 2 = 46 chromosomes total). During these steps of mitosis, the cell divides into two. So if a cell with 46 chromosomes divide into two daughter cells, then each daughter cell will have 23 chromosomes in the end. The result of mitosis: more cells with the same number of chromosomes in each cell.\n\nA cell goes through a cell cycle. Use this link to see the cell cycle: http://www.biology.arizona.edu/Cell_bio/tutorials/cell_cycle/cells2.html\n\nrelatively, mitosis is a short process.
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Karyotype\n,\n\n Karyogram of human male using Giemsa staining.A karyotype is a standardized arrangement of all the chromosomes of a cell. In normal diploid organisms, autosomal chromosomes are present in two identical copies, although polyploid cells have multiple copies of chromosomes and haploid cells have single copies. The chromosomes are arranged and displayed (often on a photo) in a standard format known as an idiogram: in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotypes are used to study chromosomal aberrations, and may be used to determine other macroscopically visible aspects of an individual's genotype, such as sex. In order to be able to see the chromosomes and determine their size and internal pattern, they are chemically labelled with a dye ("stained"). The pattern of individual chromosomes is called chromosome banding, whereas the study of whole sets of chromosomes is known as karyology.\n\nNormal human karyotypes contain 22 pairs of autosomal chromosomes and one pair of sex chromosomes. Normal karyotypes for women contain two X chromosomes and are denoted 46,XX; men have both an X and a Y chromosome denoted 46,XY. However, some individuals have other karyotypes with added or missing sex chromosomes, including 47,XYY, 47,XXY, 47,XXX and 45,X. The karyotype 45,Y does not occur, as an embryo without an X chromosome cannot survive.
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S phase is the period of synthesis.  Mitosis is the nuclear division phase. If mitosis occur before DNA duplication during  anaphase or nuclear division results imbalance chromosome number. There is also some regulatory mechanism that copletion of DNA synthesis stimulates the mitosis to occur.
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The cell cycle, or cell division cycle, is the cycle of events in a eukaryotic cell from one cell division to the next. It consists of interphase, mitosis, and usually cell division. The cell cycle is regulated by cyclins and cyclin-dependent kinases. Leland H. Hartwell, R. Timothy Hunt, and Paul M. Nurse won the 2001 Nobel Prize in Physiology or Medicine for their discovery of these central molecules in the regulation of the cell cycle.\nThe phases of the cell cycle are:\n\nThe G0 phase is a period in the cell cycle where cells exist in a quiescent state. \nThe G1 phase is the first growth phase. \nS phase, during which the DNA is replicated, where S stands for the Synthesis of DNA. \nG2 phase is the second growth phase, also the preparation phase for the cell. \nM phase or mitosis and cytokinesis, the actual division of the cell into two daughter cells. \nA surveillance system, so-called "checkpoints", monitor the cell for DNA damage and failure to perform critical processes. Checkpoints can block progression through the phases of the cell cycle if certain conditions are not met. For instance, there is a checkpoint which monitors DNA replication and keeps cells from proceeding to mitosis before DNA replication is completed. Similarly, the spindle checkpoint blocks the transition from metaphase to anaphase within mitosis if not all chromosomes are attached to the mitotic spindle.\n\nIf this system senses a problem, a network of signaling molecules instructs the cell to stop dividing. They can let the cell know whether to repair the damage or initiate programmed cell death, a form of which is called apoptosis. Programmed cell death ensures that the damaged cell is not further propagated. For example, a certain protein, called p53, acts to accept signals provoked by DNA damage. It responds by stimulating the production of inhibitory proteins that then halt the DNA replication process. Without proper p53 function, DNA damage can accumulate unchecked. A direct consequence is that the damaged gene progresses into a cancerous state. Today, defects in p53 are associated with a variety of cancers, including some breast and colon cancers.\n\nSome cells, such as neurons, never divide once they become locked in a G0 phase. However, recent data has shown that neurons undergoing cell death re-enter the cell cycle. Addition of cell cycle inhibitors prevent this type cell death called apoptosis.
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none\n\n\nyou start with one pair of homologous chromosomes in prophase I of meiosis I.  at metaphase I, these homologues line up across the metaphase plate, and at anaphase, they seperate so that one homologue goes to one pole, and the other homologue goes to the other pole.  after cytokinesis at the end of telophase I, you have one homologue in each cell...that homologue then goes through meiosis II, and at metaphase II, that homologue lines up at the metaphase plate with each sister chromatid facing each pole, and the chromosome is "pulled apart".  Anaphase II pulls the sister chromatids to each pole, and cytokinesis splits the one cell into two....two cells, each containing one sister chromatid of a homologous pair. (although in some text books this is refered to as a single homologue)
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23 pairs of chromosomes in the human body
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the correct order:\n\n1) Chromosomes copy themselves (interphase).\n2) Chromosome copies fasten together as the nuclear... (prophase).\n3) Chromosomes line up in the center of the cell (metaphase).\n4) Chromosome copies separate (anaphase & telophase).\n5) Cell splits (cytokinesis).\n\nThis is correct. Disregard the former answers.
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gametes in humans are produced through meiosis. This process produces four daughter cells, each with only half of the DNA of any other cell. Normal, or autosomal cells, have 46 chromosomes, 2 pairs of each type. Sex cells, gametes, have only one of each type chromosomes, 23 total.
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this was an AP Biology essay question not long ago\n\nIn mitosis ther are stages of always 46 chromosomes (23 pairs)\n\nIn meiosis in different stages it varies). Once the cell divides there are 23 chrmosomes
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mitosis is the process of nuclear division in which the chromosomes replicate and become equally distributed into two daughter so that they hane the same number and type of chromosomes as present in the parent. it was first observed by Strasburger(1870) in plants and by Boveri & Fleming(1879) in animal cells... its also known as somatic division as it involves only the somatic body cells, also since its keeps the chromosome numeber the same its also known as equitorial division..\n\n\nmeiosis occurs in diploid cells and gives rise to four haploid nuclei, each havin n/2 number of chromosomes, here n is the number of chromosomes.. in this the nuclei divides twice but the chromosomes are replicated only once....\n\nits divided into 2 stages\n1. Meiosis 1\n2. Meiosis 2\n\neach have a number of sub stages..\n\nthere are 1000's of major differences, i'll sorting them, its upto u to remember the one... and as far as the pneumatic device is considered, it's common 2 all of us..\n\n\n1. Mitosis takes place in somatic cells, whereas Meiosis in reproductive cells.\n\n2. mitosis occurs in both haploid & Diplois, meiosis in diploid only.\n\n3. 2 & 4 daughter cells produced resp..\n\n4. CHROMOSOMES REPLICATE IN THE INTERPHASE BEFORE EVERY DIVISON IN MITOSIS BUT IN MEIOSIS THEY REPLICATE ONLY ONCE PRIOR TO MEIOSIS.
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Mitosis is the reproduction of somatic (body) cells, while meiosis is the production of gametes (sex cells).\n\nThe normal cell has a chromosome number of "2n".  For example, a fruit fly has a chromose count of 8, so 8=2n.\n\nFollowing so far? Good.\n\nMitosis:\nMitotic division begins with a cell in Interphase, with a chromosome count of 2n.\nThe chromosomes are not visible right now under the microscope, they just look like a mass of tangled string called chromatin.\n\nIn Prophase, the chromosomes replicate, but remain attatched to their partner by a centromere (kinda look like an x).  Spindle fibres form and the centrioles migrate to the ends of the cell, opposite each other.  Nuclear membrane disappears.\n\nIn Metaphase, the chromosomes line up on the equatorial line (a bunch of x in a row along the middle of the cell), and spindle fibres attatch to each chromatid in the pair (right now, the two parts to the x are individually chromatids, but are together a chromosome).\n\nDuring Anaphase, the spindle fibres pull each daughter chromosome so that the pair of chromatids splits apart and half of them go to one end of the cell, and half to the other.\n\nDuring Telophase, the nucleolus forms and the nuclear membrane forms around the two sets of chromosomes.  A clevage furrow separates the cell into two daughter cells, each having a 2n number of chromosomes.\n\nPhew.  Still following?  Good- that was just Mitosis!\n\nNow for the fun one.  Meiosis.\nMeiosis takes the 2n cell and turns it into FOUR  (4) gametes.\nIn your body, each individual chromosome is part of a homologous pair.  That is, each has a match.  This is why we represent the chromosome number as 2n- There are two sets of n chromosomes.  In our fruit fly, the 2n number is 8, so there are 4 sets of homologous pairs.  Following? Good.\n\nMeiosis in the fruit fly begins with a single cell with 8 chromosomes, and ends with 4 cells with 4 chromosomes each.\n\nWhy does it end with "n" instead of "2n"?  Each gamete provides half the genetic information needed to create the new organism.  You get half your genes from your mother and half from your father.\n\nAnyway, meiosis takes place in two stages: aptly called meiosis 1 and meiosis 2.\n\nMeiosis 1:\nIn Interphase, the cell has roughly the same appearance as it did in Interphase of Mitosis.\n\nIn Prophase 1: The chromosomes duplicate and find their homologous pairs.  Now, the little groups istead of looking like an x, look like an x with four little lines joining, because there are 4 chromatids attached together, called a tetrad.  Understand?  I hope so!\nAt this point, the two chromatids nearest together in the tetrad may "cross over".  In other words, they swap genetic information.  Homologous pairs carry similar, but not identical coding (remember one was from your father, one from your mother).  In this way, you now have 4 chromatids that are each unique in their coding, which allows for genetic variation!  \nCentromers go to opposite ends, and spindle fibres begin to form.  Nuclear membrane disappears\n\nIn Metaphase 1: The tetrads line up on the equatorial line (remember this?)  The spindle fibres attatch to each side of the tetrad.\n\nIn Anaphase 1: The spindle fibres split the tetrads in half, so that 2 chromatids (1 chromosome now) go to one pole of the cell, and 2 chromatids (1 chromosome) go to the other.\n\nIn Telophase 1: The nuclear envelope/membrane reappears around each set of chromosomes, and a cleavage furrow splits the cell into two daughter cells.\n\nAt this point, we now have two daughter cells with "n" for the chromosome count, because there is half the amount of chromosomes we had when we started!\n\nOk, now each daughter cell undergoes meiosis 2, so that at the end we have 4 gametes.\n\nProphase 2:  Nuclear envelope dissappears.  Centroles migrate to the opposite sides of the cells, spindle fibres form.  Remember that the chromosomes are composed of
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If the total number of cells you finish with at the end of what I assume is mitosis is 36, then you began with 18 cells, which I suppose is 50%. Is that at all what you are asking?
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...DNA through a process called mitosis.
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In metaphase, the cell would have 8 chromosomes lined up in the middle, each made up of 2 sister chromatids. The microtubules are attached to the kinetochores and each sister chromatid is facing in the opposite direction of it's pair and towards one end of the cell.\n\nThe daughter cells would all have 8 chromosomes because it's mitosis, not meiosis.
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the ploidy no is 2n\nbut the dna amount is double. it changes in the metaphase or late prophase
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human cells contain 46 chromosomes\n\nthey go through a process of mitotic division that basically replicates each chromosome, the original and replicated chromosomes then migrate to opposite ends of the cells, and a cell membrane is formed, thus producing two progeny cells, division and the cycle of the cell is complete.\n\n\nmeotic division is a more complex process, but basically, the daughter cells contain 23 chromosomes, that is 1 of each pair of the 46 chromosomes is present in the daughter cell, where, whether it is a sperm or egg cell, when fused together, provide the fused cell with 46 chromosomes\n\n\n\n\nhope it helped you understand it a little better\n\nthere are however, different phases to the division process and if you like I can send you a link, depends on how much you want to know at present?