Cyclin E is known as?
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G-1 S Phase Regulatory Protein
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You would find that many cells spend the majority of the cell cycle in G0/G1 phase as opposed to the actively dividing root tip sections you saw. \n\nPlease visit the link I have provided from the Univ. of Arizona- it describes the Onion Root Tip as well as each phase. This should reinforce some concepts as well.\n\nGood luck!
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Oncogenes are mutated genes that contribute to cancer development by disrupting a cell’s ability to control its own growth and DNA repair mechanisms2,5. Normally mitosis (cell division) is a carefully regulated event, requiring the activation of one protein to activate another, in what is known as a signal transduction cascade. This cascade eventually culminates in changes in gene expression that prepares the cell for mitotic events.\n\nOncogenes are mutated forms of proto-oncogenes; these genes are often involved in growth signalling and anti-apoptotic pathways. When proto-oncogenes mutate to become oncogenes they retain their functionality, but are no longer capable of responding to normal regulatory signals (see Figure 1).
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e\n___d_____________\n         c\n___b__________________\n        a\n__g____________________\n      f\n_______________________
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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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1. Prophase 2. Metaphase 3. Anaphase 4.Teleohase
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http://www.iknow.net/CDROMs/cell_cdrom/index.shtml\n\nCheck this site out! It has both plant and animal cell division! Hope it helps ya!! =o)
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two cell divisions.... one for meiosis 1 and one for meiosis 2
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Introduction. This is a brief outline of the steps necessary to produce mice with a mutation targeted to a specific gene. These animals are referred to as "knock-out" mice or "gene targeted" mice. The broad outline of the experiment includes: 1) the investigator constructs a gene targeting vector containing a mutation in the target gene; 2) the targeting vector is introduced into ES cells; 3) ES cell clones which undergo homologous recombination with the targeting vector are identified; 4) ES cell-mouse chimeras are produced; 5) the chimeras breed and transmit the chromosome with the targeted gene to their offspring; 6) homozygous animals are produced from the mating of hemizygous chimera offspring; and 7) the phenotype resulting from the genetic mutation is characterized. Core personnel are available for consultation on all aspects of gene targeting research. Contact Thom Saunders with any questions or Meet the Staff.  The Transgenic Core prioritizes all requests for service on a "first-come, first-serve" basis. Your requests for electroporation, clone expansion, and blastocyst microinjection will be added to the Transgenic Core work queue in the order that they are received. \n2. Plan the experiment. What is the purpose of your experiment? Do you want to completely ablate gene expression in all tissues? Do you want to analyze tissue specific regulatory sequences? Do you want to produce a model for tissue-specific gene deletions? You will need to obtain or clone the structural gene that you want to mutate. The source of the DNA is important since published studies demonstrate genomic DNA isogenic to the embryonic stem cell line give higher gene targeting efficiencies in ES cells (see Key Gene Targeting Papers). While complete sequence information is not necessary, a detailed restriction map of the gene is an irreplaceable tool. During the planning stages the material transfer agreements for R1 ES cells and other reagents should be initiated so that they are ready in time. Once a genomic clone of the gene is in hand and restriction mapped, then it is time to... \n\n3. Clone and the Verify the Targeting Vector. The Core has cloning vectors for investigators to use in gene targeting research. They include pPNT, a basic targeting vector, pNZTK2, designed to insert the lacZ gene behind the promoter of the targeted gene, and pflox, which is designed to introduce loxP sites into the gene. A complete materials transfer agreement is required before they can be distributed. You will need to determine which 5' and 3' fragments of the gene will be used to construct the targeting vector. Generally speaking, a couple of Kb on either end should give a reasonable gene targeting frequency. You will also need to consider the methods and probes that you will use to identify ES cell clones that have undergone homologous recombination with the targeting vector. This means a Southern blot approach with probes outside of the targeting vector or a PCR based assay with primers outside of the targeting vector. Once the orientation of the fragments in the targeting vector are confirmed and the probes are tested then it is time to... \n\n4. Electroporate ES Cells and Select Recombinants. ES cells are a very sensitive reagent, and most often the weakest link in the process of producing gene targeted mice. Fastidious tissue culture technique is necessary to maintain the totipotent state of the cells during electroporation, selection, and expansion. In order to maximize successful outcomes, the Transgenic Core maintains ES cells and companion reagents that are quality tested by producing ES cell-mouse chimeras that transmit the ES cell genome to offspring. Investigators may choose to use the Core's Gene Targeting Service (we do all of the tissue culture work, you do all of the molecular biology), or to use space in the Core lab (rent space in our completely equipped laboratory for ES cell culture work), or to do th
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The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. It was discovered in 1888 by Theodor Boveri and was described as the 'especial organ of cell division.' Although the centrosome has a key role in efficient cell division, it has been recently shown that it is not necessary [1].\n\nCentrosomes are composed of two orthogonally arranged centrioles surrounded by an amorphous mass of pericentriolar material (PCM). The PCM tethers proteins responsible for microtubule nucleation and anchoring, γ-tubulin, pericentrin and ninein. Each centriole is comprised of nine triplet microtubule blades in a pinwheel structure as well as centrin, cenexin and tektin [1].
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Definitely b...\nDuring Interphase, there are 3 subphases - G1, S, and G2.  G1 is for growth of the cell, S is for synthesis of an extra set of chromosomes (amount of DNA in cells), and G2 is for preparation for the rest of cell division.  After interphase is prophase (nuclear membrane dissolves and DNA bundles up), then metaphase (DNA lines up on the center of the cell), anaphase (DNA separates towards poles), and telophase (Cell divides into two cells).  I hope this helps!\n\nAnswer: b. between the G1 and G2 phases of the cell cycle
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G.W. Jr. Shipps, U.P. Spitz, J. Jr. Rebek, Solution-Phase Generation of Tetraurea Libraries, Bioorganic & Medicinal Chemistry \nfound at the site... \nhttp://www1.elsevier.com/cdweb/journals/09680896/viewer.htt?viewtype=keywords&rangeselected=32\n\nlooks like fun stuff :) don't inhale
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Wikipedia's entry is very good on the phases of mitosis:\nhttp://jove.geol.niu.edu/faculty/stoddard/JAVA/luminaries.html
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http://en.wikipedia.org/wiki/Kreb%27s_cycle
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This any good\n\nhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9473085&dopt=Abstract
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G1 - chromatin\nS - chromosomes\nG2 - chromatin\nMitosis - chromosomes (the chromosomes become less condensed in telophase though)\nCytokinesis - chromatin\n\nDuring all three subphases, the cell grows by producing protiens and cytoplasmic organelles such as mitochondria and endoplasmic reticulum.  However, chromosomes are duplicated only during the S phase.  Thus, a cell grows (G1), continues to grow as it copies its chromosomes (S), grows more as it completes preparations for cell division (G2), and divides (M).  I'm guessing cell growth is fastest in G1 but im not sure, so dont quote me.\nHope I helped =)
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the letter "E"...good one! ;P