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Prophase
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<h2 id="staining-and-microscopy">Staining and microscopy</h2> <p><a href="/facts/Microscopy/GpHlElDS">Microscopy</a> can be used to visualize condensed <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> as they move through <a href="/facts/Meiosis/Pj5Q6nGN">meiosis</a> and <a href="/facts/Mitosis/ExxrSUs8">mitosis</a>.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> </p><p>Various DNA <a href="/facts/Staining/jqGqWEE1">stains</a> are used to treat cells such that condensing <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> can be visualized as the move through prophase.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p><p>The <a href="/facts/Giemsa_stain/qkA81qvW">giemsa</a> <a href="/facts/G_banding/dEuKPThJ">G-banding</a> technique is commonly used to identify <a href="/facts/Mammal/phSwTzBo">mammalian</a> <a href="/facts/Chromosome/FRGf11FC">chromosomes</a>, but utilizing the technology on <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a> was originally difficult due to the high degree of chromosome compaction in plant cells.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a><a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> <a href="/facts/G_banding/dEuKPThJ">G-banding</a> was fully realized for plant chromosomes in 1990.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> During both <a href="/facts/Meiosis/Pj5Q6nGN">meiotic</a> and <a href="/facts/Mitosis/ExxrSUs8">mitotic</a> prophase, <a href="/facts/Giemsa_stain/qkA81qvW">giemsa staining</a> can be applied to cells to elicit <a href="/facts/G_banding/dEuKPThJ">G-banding</a> in <a href="/facts/Chromosome/FRGf11FC">chromosomes</a>.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> Silver staining, a more modern technology, in conjunction with <a href="/facts/Giemsa_stain/qkA81qvW">giemsa staining</a> can be used to image the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> throughout the various stages of <a href="/facts/Meiosis/Pj5Q6nGN">meiotic</a> prophase.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> To perform <a href="/facts/G_banding/dEuKPThJ">G-banding</a>, <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> must be fixed, and thus it is not possible to perform on living cells.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> </p><p><a href="/facts/Fluorescence_microscope/eMwIdrRR">Fluorescent stains</a> such as <a href="/facts/DAPI/3op6tcmN">DAPI</a> can be used in both live <a href="/facts/Plant_cell/T4RqyI2f">plant</a> and <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a>. These stains do not band <a href="/facts/Chromosome/FRGf11FC">chromosomes</a>, but instead allow for DNA probing of specific regions and <a href="/facts/Gene/e1swwPY6">genes</a>. Use of <a href="/facts/Fluorescence_microscope/eMwIdrRR">fluorescent microscopy</a> has vastly improved <a href="/facts/Spatial_resolution/ll8LNYxN">spatial resolution</a>.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> </p> <h2 id="mitotic-prophase">Mitotic prophase</h2> <p>Prophase is the first stage of <a href="/facts/Mitosis/ExxrSUs8">mitosis</a> in <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a>, and the second stage of <a href="/facts/Mitosis/ExxrSUs8">mitosis</a> in <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> At the start of prophase there are two identical copies of each <a href="/facts/Chromosome/FRGf11FC">chromosome</a> in the cell due to replication in <a href="/facts/Interphase/c37v07K4">interphase</a>. These copies are referred to as <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a> and are attached by <a href="/facts/DNA/nB89Iauz">DNA</a> element called the <a href="/facts/Centromere/AWxF1ClY">centromere</a>.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> The main events of prophase are: the condensation of <a href="/facts/Chromosome/FRGf11FC">chromosomes</a>, the movement of the <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a>, the formation of the <a href="/facts/Spindle_apparatus/FMFd1GM5">mitotic spindle</a>, and the beginning of <a href="/facts/Nucleolus/X7B5HKM4">nucleoli</a> break down.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p> <h3>Condensation of chromosomes</h3> <p><a href="/facts/DNA/nB89Iauz">DNA</a> that was <a href="/facts/DNA_replication/wrU6RuR3">replicated</a> in <a href="/facts/Interphase/c37v07K4">interphase</a> is condensed from DNA strands with lengths reaching 0.7 μm down to 0.2-0.3 μm.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> This process employs the <a href="/facts/Condensin/fl4tzfpm">condensin</a> complex.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> Condensed chromosomes consist of two <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a> joined at the <a href="/facts/Centromere/AWxF1ClY">centromere</a>.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p> <h3>Movement of centrosomes</h3> <p>During prophase in <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a>, <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> move far enough apart to be resolved using a <a href="/facts/Light_microscope/5700vcna">light microscope</a>.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> <a href="/facts/Microtubule/ENL1TxSe">Microtubule</a> activity in each <a href="/facts/Centrosome/QlTtIIeI">centrosome</a> is increased due to recruitment of <a href="/facts/Tubulin/j4Bk2wcL">γ-tubulin</a>. Replicated <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> from <a href="/facts/Interphase/c37v07K4">interphase</a> move apart towards opposite poles of the cell, powered by <a href="/facts/Motor_protein/g5PE2m9F">centrosome associated motor proteins</a>.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> Interdigitated interpolar <a href="/facts/Microtubule/ENL1TxSe">microtubules</a> from each <a href="/facts/Centrosome/QlTtIIeI">centrosome</a> interact with each other, helping to move the <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> to opposite poles.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a><a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> </p> <h3>Formation of the mitotic spindle</h3> <p><a href="/facts/Microtubule/ENL1TxSe">Microtubules</a> involved in the <a href="/facts/Interphase/c37v07K4">interphase</a> scaffolding break down as the replicated <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> separate.<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> The movement of <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> to opposite poles is accompanied in <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a> by the organization of individual radial <a href="/facts/Microtubule/ENL1TxSe">microtubule</a> arrays (asters) by each centriole.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> Interpolar <a href="/facts/Microtubule/ENL1TxSe">microtubules</a> from both <a href="/facts/Centrosome/QlTtIIeI">centrosomes</a> interact, joining the sets of <a href="/facts/Microtubule/ENL1TxSe">microtubules</a> and forming the basic structure of the <a href="/facts/Spindle_apparatus/FMFd1GM5">mitotic spindle</a>.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a> Plant cells do not have centrosomes and the <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> can <a href="/facts/Nucleation/efUVLsLR">nucleate</a> <a href="/facts/Microtubule/ENL1TxSe">microtubule</a> assembly into the <a href="/facts/Spindle_apparatus/FMFd1GM5">mitotic apparatus</a>.<a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a> In <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a>, <a href="/facts/Microtubule/ENL1TxSe">microtubules</a> gather at opposite poles and begin to form the <a href="/facts/Spindle_apparatus/FMFd1GM5">spindle apparatus</a> at locations called foci.<a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a> The <a href="/facts/Spindle_apparatus/FMFd1GM5">mitotic spindle</a> is of great importance in the process of <a href="/facts/Mitosis/ExxrSUs8">mitosis</a> and will eventually segregate the <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a> in <a href="/facts/Metaphase/WMPlWk8s">metaphase</a>.<a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> </p> <h3>Beginning of nucleoli breakdown</h3> <p>The <a href="/facts/Nucleolus/X7B5HKM4">nucleoli</a> begin to break down in prophase, resulting in the discontinuation of ribosome production.<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> This indicates a redirection of cellular energy from general cellular metabolism to <a href="/facts/Cell_division/n5MrunWj">cellular division</a>.<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> The <a href="/facts/Nuclear_membrane/IwRQ5BVL">nuclear envelope</a> stays intact during this process.<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> </p> <h2 id="meiotic-prophase">Meiotic prophase</h2> <p><a href="/facts/Meiosis/Pj5Q6nGN">Meiosis</a> involves two rounds of <a href="/facts/Chromosome_segregation/wvIl1RoC">chromosome segregation</a> and thus undergoes prophase twice, resulting in prophase I and prophase II.<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a> Prophase I is the most complex phase in all of meiosis because <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a> must pair and exchange <a href="/facts/Nucleic_acid_sequence/qAf4kTee">genetic information</a>.<a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a>: 98 Prophase II is very similar to <a href="/facts/Mitosis/ExxrSUs8">mitotic</a> prophase.<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> </p> <h3>Prophase I</h3> <p>Prophase I is divided into five phases: leptotene, zygotene, pachytene, diplotene, and diakinesis. In addition to the events that occur in <a href="/facts/Mitosis/ExxrSUs8">mitotic</a> prophase, several crucial events occur within these phases such as pairing of <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a> and the reciprocal <a href="/facts/Chromosomal_crossover/UKewoPa2">exchange of genetic material</a> between these <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a>. Prophase I occurs at different speeds dependent on <a href="/facts/Species/oDg6b96r">species</a> and <a href="/facts/Sex/ssBol2pP">sex</a>. Many species arrest <a href="/facts/Meiosis/Pj5Q6nGN">meiosis</a> in diplotene of prophase I until <a href="/facts/Ovulation/0K3MLdAv">ovulation</a>.<a class="footnote-ref" id="fnref:33" href="#fn:33"><sup>33</sup></a>: 98 In humans, decades can pass as <a href="/facts/Oocyte/aYrWtc3n">oocytes</a> remain arrested in prophase I only to quickly complete meiosis I prior to <a href="/facts/Ovulation/0K3MLdAv">ovulation</a>.<a class="footnote-ref" id="fnref:34" href="#fn:34"><sup>34</sup></a> </p> <h4>Leptotene</h4> <p class="note">Main article: <a href="/facts/Leptotene_stage/UUqjXHLE">Leptotene stage</a></p> <p>In the first stage of prophase I, leptotene (from the Greek for "delicate"), <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> begin to condense. Each chromosome is in a <a href="/facts/Ploidy/U8zl4AQe">diploid</a> state and consists of two <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a>; however, the <a href="/facts/Chromatin/ha0TJheJ">chromatin</a> of the <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a> is not yet condensed enough to be resolvable in <a href="/facts/Microscopy/GpHlElDS">microscopy</a>.<a class="footnote-ref" id="fnref:35" href="#fn:35"><sup>35</sup></a>: 98 <a href="/facts/Homology_(biology)/muctKlyT">Homologous</a> regions within <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosome</a> pairs begin to associate with each other.<a class="footnote-ref" id="fnref:36" href="#fn:36"><sup>36</sup></a> </p> <h4>Zygotene</h4> <p>In the second phase of prophase I, zygotene (from the Greek for "conjugation"), all maternally and paternally derived <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> have found their <a href="/facts/Homologous_chromosome/hktsBhyx">homologous</a> partner.<a class="footnote-ref" id="fnref:37" href="#fn:37"><sup>37</sup></a>: 98 The homologous pairs then undergo synapsis,a process by which the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> (a proteinaceous structure) aligns corresponding regions of <a href="/facts/Nucleic_acid_sequence/qAf4kTee">genetic information</a> on maternally and paternally derived non-sister <a href="/facts/Chromatid/fQ68yxMn">chromatids</a> of <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosome</a> pairs.<a class="footnote-ref" id="fnref:38" href="#fn:38"><sup>38</sup></a>: 98 <a class="footnote-ref" id="fnref:39" href="#fn:39"><sup>39</sup></a> The paired homologous chromosome bound by the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> are referred to as <a href="/facts/Bivalent_(genetics)/oLdDCGHb">bivalents</a> or tetrads.<a class="footnote-ref" id="fnref:40" href="#fn:40"><sup>40</sup></a><a class="footnote-ref" id="fnref:41" href="#fn:41"><sup>41</sup></a>: 98 <a href="/facts/Allosome/PGYGkTQM">Sex (X and Y) chromosomes</a> do not fully synapse because only a small region of the chromosomes are homologous.<a class="footnote-ref" id="fnref:42" href="#fn:42"><sup>42</sup></a>: 98 </p><p>The <a href="/facts/Nucleolus/X7B5HKM4">nucleolus</a> moves from a central to a peripheral position in the <a href="/facts/Cell_nucleus/D7sFRa3c">nucleus</a>.<a class="footnote-ref" id="fnref:43" href="#fn:43"><sup>43</sup></a> </p> <h4>Pachytene</h4> <p>The third phase of prophase I, pachytene (from the Greek for "thick"), begins at the completion of synapsis.<a class="footnote-ref" id="fnref:44" href="#fn:44"><sup>44</sup></a>: 98 <a href="/facts/Chromatin/ha0TJheJ">Chromatin</a> has condensed enough that <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> can now be resolved in <a href="/facts/Microscopy/GpHlElDS">microscopy</a>.<a class="footnote-ref" id="fnref:45" href="#fn:45"><sup>45</sup></a> Structures called recombination nodules form on the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> of <a href="/facts/Bivalent_(genetics)/oLdDCGHb">bivalents</a>. These recombination nodules facilitate <a href="/facts/Chromosomal_crossover/UKewoPa2">genetic exchange</a> between the non-sister chromatids of the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> in an event known as <a href="/facts/Chromosomal_crossover/UKewoPa2">crossing-over</a> or genetic recombination.<a class="footnote-ref" id="fnref:46" href="#fn:46"><sup>46</sup></a>: 98 Multiple recombination events can occur on each bivalent. In humans, an average of 2-3 events occur on each chromosome.<a class="footnote-ref" id="fnref:47" href="#fn:47"><sup>47</sup></a>: 681 </p> <h4>Diplotene</h4> <p>In the fourth phase of prophase I, diplotene (from the Greek for "twofold"), <a href="/facts/Chromosomal_crossover/UKewoPa2">crossing-over</a> is completed.<a class="footnote-ref" id="fnref:48" href="#fn:48"><sup>48</sup></a>: 99 <a class="footnote-ref" id="fnref:49" href="#fn:49"><sup>49</sup></a> <a href="/facts/Homologous_chromosome/hktsBhyx">Homologous chromosomes</a> retain a full set of genetic information; however, the <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a> are now of mixed maternal and paternal descent.<a class="footnote-ref" id="fnref:50" href="#fn:50"><sup>50</sup></a>: 99 Visible junctions called chiasmata hold the <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a> together at locations where recombination occurred as the <a href="/facts/Synaptonemal_complex/vTadctRx">synaptonemal complex</a> dissolves.<a class="footnote-ref" id="fnref:51" href="#fn:51"><sup>51</sup></a><a class="footnote-ref" id="fnref:52" href="#fn:52"><sup>52</sup></a>: 99 It is at this stage where meiotic arrest occurs in many <a href="/facts/Species/oDg6b96r">species</a>.<a class="footnote-ref" id="fnref:53" href="#fn:53"><sup>53</sup></a>: 99 </p> <h4>Diakinesis</h4> <p>In the fifth and final phase of prophase I, diakinesis (from the Greek for "double movement"), full chromatin condensation has occurred and all four <a href="/facts/Sister_chromatids/pqqWuKII">sister chromatids</a> can be seen in <a href="/facts/Bivalent_(genetics)/oLdDCGHb">bivalents</a> with <a href="/facts/Microscopy/GpHlElDS">microscopy</a>. The rest of the phase resemble the early stages of mitotic <a href="/facts/Prometaphase/S00Vvf2C">prometaphase</a>, as the meiotic prophase ends with the <a href="/facts/Spindle_apparatus/FMFd1GM5">spindle apparatus</a> beginning to form, and the <a href="/facts/Nuclear_membrane/IwRQ5BVL">nuclear membrane</a> beginning to break down.<a class="footnote-ref" id="fnref:54" href="#fn:54"><sup>54</sup></a><a class="footnote-ref" id="fnref:55" href="#fn:55"><sup>55</sup></a>: 99 </p> <h3>Prophase II</h3> <p>Prophase II of <a href="/facts/Meiosis/Pj5Q6nGN">meiosis</a> is very similar to prophase of <a href="/facts/Mitosis/ExxrSUs8">mitosis</a>. The most noticeable difference is that prophase II occurs with a <a href="/facts/Ploidy/U8zl4AQe">haploid</a> number of <a href="/facts/Chromosome/FRGf11FC">chromosomes</a> as opposed to the <a href="/facts/Ploidy/U8zl4AQe">diploid</a> number in mitotic prophase.<a class="footnote-ref" id="fnref:56" href="#fn:56"><sup>56</sup></a><a class="footnote-ref" id="fnref:57" href="#fn:57"><sup>57</sup></a> In both <a href="/facts/Cell_(biology)/bLM9UQvy">animal</a> and <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a> chromosomes may de-condense during <a href="/facts/Telophase/c4eAwvmD">telophase</a> I requiring them to re-condense in prophase II.<a class="footnote-ref" id="fnref:58" href="#fn:58"><sup>58</sup></a>: 100 <a class="footnote-ref" id="fnref:59" href="#fn:59"><sup>59</sup></a> If chromosomes do not need to re-condense, prophase II often proceeds very quickly as is seen in the <a href="/facts/Model_organism/vNv6q4yb">model organism</a> <a href="/facts/Arabidopsis/SCz1CG26">Arabidopsis</a>.<a class="footnote-ref" id="fnref:60" href="#fn:60"><sup>60</sup></a> </p> <h2 id="prophase-i-arrest">Prophase I arrest</h2> <p>Female mammals and birds are born possessing all the oocytes needed for future ovulations, and these <a href="/facts/Oocyte/aYrWtc3n">oocytes</a> are arrested at the prophase I stage of <a href="/facts/Meiosis/Pj5Q6nGN">meiosis</a>.<a class="footnote-ref" id="fnref:61" href="#fn:61"><sup>61</sup></a> In humans, as an example, oocytes are formed between three and four months of <a href="/facts/Gestation/QKgkykw5">gestation</a> within the fetus and are therefore present at birth. During this prophase I arrested stage (<a href="/facts/Dictyate/AC9neESR">dictyate</a>), which may last for decades, four copies of the <a href="/facts/Genome/31Sm08JT">genome</a> are present in the oocytes. The adaptive significance of prophase I arrest is still not fully understood. However, it has been proposed that the arrest of oocytes at the four genome copy stage may provide the informational redundancy needed to <a href="/facts/DNA_repair/hsURuYYq">repair damage in the DNA</a> of the <a href="/facts/Germline/QI4bKK8Q">germline</a>.<a class="footnote-ref" id="fnref:62" href="#fn:62"><sup>62</sup></a> The repair process used appears to be <a href="/facts/Homologous_recombination/WU0IIVVv">homologous recombinational</a> repair<a class="footnote-ref" id="fnref:63" href="#fn:63"><sup>63</sup></a><a class="footnote-ref" id="fnref:64" href="#fn:64"><sup>64</sup></a> Prophase arrested oocytes have a high capability for efficient repair of <a href="/facts/DNA_damage_(naturally_occurring)/CjGTLKGl">DNA damages</a>.<a class="footnote-ref" id="fnref:65" href="#fn:65"><sup>65</sup></a> DNA repair capability appears to be a key quality control mechanism in the female germ line and a critical determinant of <a href="/facts/Fertility/5S7Xull5">fertility</a>.<a class="footnote-ref" id="fnref:66" href="#fn:66"><sup>66</sup></a> </p> <h2 id="differences-in-plant-and-animal-cell-prophase">Differences in plant and animal cell prophase</h2> <p>The most notable difference between prophase in <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a> and <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a> occurs because plant cells lack <a href="/facts/Centriole/yphJbFlH">centrioles</a>. The organization of the <a href="/facts/Spindle_apparatus/FMFd1GM5">spindle apparatus</a> is associated instead with foci at opposite poles of the cell or is mediated by chromosomes. Another notable difference is <a href="/facts/Preprophase/lMU3shrd">preprophase</a>, an additional step in plant <a href="/facts/Mitosis/ExxrSUs8">mitosis</a> that results in formation of the <a href="/facts/Preprophase_band/ETkmq2Bj">preprophase band</a>, a structure composed of <a href="/facts/Microtubule/ENL1TxSe">microtubules</a>. In <a href="/facts/Mitosis/ExxrSUs8">mitotic</a> prophase I of plants, this band disappears.<a class="footnote-ref" id="fnref:67" href="#fn:67"><sup>67</sup></a> </p> <h2 id="cell-checkpoints">Cell checkpoints</h2> <p>Prophase I in <a href="/facts/Meiosis/Pj5Q6nGN">meiosis</a> is the most complex iteration of prophase that occurs in both <a href="/facts/Plant_cell/T4RqyI2f">plant cells</a> and <a href="/facts/Cell_(biology)/bLM9UQvy">animal cells</a>.<a class="footnote-ref" id="fnref:68" href="#fn:68"><sup>68</sup></a> To ensure pairing of <a href="/facts/Homologous_chromosome/hktsBhyx">homologous chromosomes</a> and <a href="/facts/Homologous_recombination/WU0IIVVv">recombination of genetic material</a> occurs properly, there are <a href="/facts/Cell_cycle_checkpoint/lLda9WDW">cellular checkpoints</a> in place. The meiotic checkpoint network is a <a href="/facts/DNA_damage/hsURuYYq">DNA damage</a> response system that controls <a href="/facts/DNA_repair/hsURuYYq">double strand break</a> repair, <a href="/facts/Chromatin/ha0TJheJ">chromatin</a> structure, and the movement and pairing of <a href="/facts/Chromosome/FRGf11FC">chromosomes</a>.<a class="footnote-ref" id="fnref:69" href="#fn:69"><sup>69</sup></a> The system consists of multiple pathways (including the <a href="/facts/Meiotic_recombination_checkpoint/7JcjjSbe">meiotic recombination checkpoint</a>) that prevent the cell from entering <a href="/facts/Metaphase_I/Pj5Q6nGN">metaphase I</a> with errors due to recombination.<a class="footnote-ref" id="fnref:70" href="#fn:70"><sup>70</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Prometaphase/S00Vvf2C">Prometaphase</a></li> <li><a href="/facts/Metaphase/WMPlWk8s">Metaphase</a></li> <li><a href="/facts/Anaphase/mcGBl6Q5">Anaphase</a></li> <li><a href="/facts/Telophase/c4eAwvmD">Telophase</a></li> <li><a href="/facts/Meiosis/Pj5Q6nGN">Meiosis</a></li> <li><a href="/facts/Mitosis/ExxrSUs8">Mitosis</a></li> <li><a href="/facts/Cytoskeleton/1sWlJRX9">Cytoskeleton</a></li> <li><a href="/facts/Homologous_chromosome/hktsBhyx">Homologous chromosome</a></li></ul> <h2 id="external-links">External links</h2> <ul><li> Media related to Prophase at Wikimedia Commons</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Singh RJ (2017). Plant Cytogenetics (Third ed.). Boca Raton, FL: CBC Press, Taylor & Francis Group. p. 19. ISBN 9781439884188. <a href="9781439884188" target="_blank">9781439884188</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Singh RJ (2017). Plant Cytogenetics (Third ed.). Boca Raton, FL: CBC Press, Taylor & Francis Group. p. 19. ISBN 9781439884188. <a href="9781439884188" target="_blank">9781439884188</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Wang HC, Kao KN (1988). "G-banding in plant chromosomes". Genome. 30: 48–51. doi:10.1139/g88-009. S2CID 83823255 – via ResearchGate. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Singh RJ (2017). Plant Cytogenetics (Third ed.). Boca Raton, FL: CBC Press, Taylor & Francis Group. p. 19. ISBN 9781439884188. <a href="9781439884188" target="_blank">9781439884188</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Kakeda K, Yamagata H, Fukui K, Ohno M, Fukui K, Wei ZZ, Zhu ES (August 1990). "High resolution bands in maize chromosomes by G-banding methods". Theoretical and Applied Genetics. 80 (2): 265–72. doi:10.1007/BF00224397. PMID 24220906. S2CID 6600449. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Schermelleh L, Carlton PM, Haase S, Shao L, Winoto L, Kner P, et al. (June 2008). "Subdiffraction multicolor imaging of the nuclear periphery with 3D structured illumination microscopy". Science. 320 (5881): 1332–36. Bibcode:2008Sci...320.1332S. doi:10.1126/science.1156947. PMC 2916659. PMID 18535242. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916659" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916659</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Pathak S, Hsu TC (January 1979). "Silver-stained structures in mammalian meiotic prophase". Chromosoma. 70 (2): 195–203. doi:10.1007/bf00288406. PMID 85512. S2CID 27763957. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Sumner AT (May 1982). "The nature and mechanisms of chromosome banding". Cancer Genetics and Cytogenetics. 6 (1): 59–87. doi:10.1016/0165-4608(82)90022-x. PMID 7049353. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>de Jong H (December 2003). "Visualizing DNA domains and sequences by microscopy: a fifty-year history of molecular cytogenetics". Genome. 46 (6): 943–6. doi:10.1139/g03-107. PMID 14663510. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Zeng XL, Jiao MD, Wang XG, Song ZX, Rao S (2001). "Electron microscopic studies on the Silver-stained Nucleolar Cycle of Physarum Polycephalum" (PDF). Acta Botanica Sinica. 43 (7): 680–5. Archived from the original (PDF) on 2018-10-01. Retrieved 24 February 2015. <a href="https://web.archive.org/web/20181001070430/http://www.jipb.net/pubsoft/content/2/2071/X000541(PS2).pdf" target="_blank">https://web.archive.org/web/20181001070430/http://www.jipb.net/pubsoft/content/2/2071/X000541(PS2).pdf</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Zeng XL, Jiao MD, Wang XG, Song ZX, Rao S (2001). "Electron microscopic studies on the Silver-stained Nucleolar Cycle of Physarum Polycephalum" (PDF). Acta Botanica Sinica. 43 (7): 680–5. Archived from the original (PDF) on 2018-10-01. Retrieved 24 February 2015. <a href="https://web.archive.org/web/20181001070430/http://www.jipb.net/pubsoft/content/2/2071/X000541(PS2).pdf" target="_blank">https://web.archive.org/web/20181001070430/http://www.jipb.net/pubsoft/content/2/2071/X000541(PS2).pdf</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> <li id="fn:20"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></p></li> <li id="fn:21"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></p></li> <li id="fn:22"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></p></li> <li id="fn:23"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></p></li> <li id="fn:24"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></p></li> <li id="fn:25"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></p></li> <li id="fn:26"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></p></li> <li id="fn:27"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></p></li> <li id="fn:28"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></p></li> <li id="fn:29"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></p></li> <li id="fn:30"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></p></li> <li id="fn:31"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></p></li> <li id="fn:32"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></p></li> <li id="fn:33"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></p></li> <li id="fn:34"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></p></li> <li id="fn:35"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></p></li> <li id="fn:36"><p>Schermelleh L, Carlton PM, Haase S, Shao L, Winoto L, Kner P, et al. (June 2008). "Subdiffraction multicolor imaging of the nuclear periphery with 3D structured illumination microscopy". Science. 320 (5881): 1332–36. Bibcode:2008Sci...320.1332S. doi:10.1126/science.1156947. PMC 2916659. PMID 18535242. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916659" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916659</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></p></li> <li id="fn:37"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:37" class="footnote-back-ref">↩</a></p></li> <li id="fn:38"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></p></li> <li id="fn:39"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:39" class="footnote-back-ref">↩</a></p></li> <li id="fn:40"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:40" class="footnote-back-ref">↩</a></p></li> <li id="fn:41"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:41" class="footnote-back-ref">↩</a></p></li> <li id="fn:42"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:42" class="footnote-back-ref">↩</a></p></li> <li id="fn:43"><p>Zickler D, Kleckner N (1998). "The leptotene-zygotene transition of meiosis". Annual Review of Genetics. 32: 619–97. doi:10.1146/annurev.genet.32.1.619. PMID 9928494. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:43" class="footnote-back-ref">↩</a></p></li> <li id="fn:44"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:44" class="footnote-back-ref">↩</a></p></li> <li id="fn:45"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:45" class="footnote-back-ref">↩</a></p></li> <li id="fn:46"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:46" class="footnote-back-ref">↩</a></p></li> <li id="fn:47"><p>Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2004). Essential Cell Biology. New York NY: Garland Science. pp. 639–658. ISBN 978-0-8153-3481-1. <a href="978-0-8153-3481-1" target="_blank">978-0-8153-3481-1</a> <a href="#fnref:47" class="footnote-back-ref">↩</a></p></li> <li id="fn:48"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:48" class="footnote-back-ref">↩</a></p></li> <li id="fn:49"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. ISBN 978-1-60535-255-8. <a href="978-1-60535-255-8" target="_blank">978-1-60535-255-8</a> <a href="#fnref:49" class="footnote-back-ref">↩</a></p></li> <li id="fn:50"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:50" class="footnote-back-ref">↩</a></p></li> <li id="fn:51"><p>Nussbaum RL, McInnes RR, Willard HF (2016). Thompson & Thompson Genetics in Medicine. Philadelphia: Elsevier. pp. 12–20. ISBN 978-1-4377-0696-3. <a href="978-1-4377-0696-3" target="_blank">978-1-4377-0696-3</a> <a href="#fnref:51" class="footnote-back-ref">↩</a></p></li> <li id="fn:52"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:52" class="footnote-back-ref">↩</a></p></li> <li id="fn:53"><p>Hartwell LH, Hood L, Goldberg ML, Reynolds AE, Silver LM, Veres RC (2008). Genetics From Genes to Genomes. New York: McGraw-Hill. pp. 90–103. ISBN 978-0-07-284846-5. <a href="978-0-07-284846-5" target="_blank">978-0-07-284846-5</a> <a href="#fnref:53" class="footnote-back-ref">↩</a></p></li> <li id="fn:54"><p>Taiz L, Zeiger E, Moller IM, Murphy A (2015). Plant Physiology and Development. Sunderland MA: Sinauer Associates. pp. 35–39. 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