许迦南吧 关注:6贴子:482
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1. why do chromosomes condense and thicken during prophase, unwind during telophase?
2. why is telophase drawn as cytokinesis on most diagrams, when the division of the cytoplasm is AFTER telophase, DURING CYTOKINESIS??
3.when exactly--during which phases, does the nucleolus disappear/reappear?
4.are "purebred" and "true bred" the same as "homozygous"
5. "Explain the meanings of Mendel’s principle of
segregation and principle of independent
assortment. Under what circumstances does
the principle of independent assortment hold
true? Give an example in which this law does
not apply."
what?? there are exceptions? = =



IP属地:加拿大1楼2011-01-09 09:05回复
    6. chromosomes?(double?) chromatin?(coiled? uncoiled?) chromatid?(single?)


    IP属地:加拿大2楼2011-01-09 09:07
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      mitosis:
      46 replicated chromosomes -> 46 (unreplicated) chromatids
      meiosis:
      46 replicated chromosomes -> 23 replicated chromosomes -> 23 (unreplicated) chromatids
      7. crossing over
      does it happen once (during meiosis I-prophase I) or twice (during both meiosis I-prophase I, and meiosis II -prophase II ?)
      


      IP属地:加拿大3楼2011-01-09 09:10
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        回复:3楼
        7. it only happens in prophase I!
        who wrote "allows recombination of genes in each chromosome"?!
        oh yea right, JENNY= =!
        http://en.wikip(harmony??really seriously?!)edia.org/wiki/Chromosomal_crossover
        


        IP属地:加拿大4楼2011-01-09 09:15
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          8. is oocyte the bigger 1 of the 2 cells at the end of meiosis I or the biggest of all 4 cells at the end of meiosis II
          9. "in females, meiosis II occurs after the egg is fertilized by a sperm cell."
          can be after? or only after?
          how does a cell go through division when there's a sperm in it??
          


          IP属地:加拿大5楼2011-01-09 09:38
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            2.is cytokenisis considered part of mitosis


            IP属地:加拿大6楼2011-01-09 09:41
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              10.if there's no telophase I...what happens to:
              nulear memberane?
              nuleolus?
              centriols & spindle fibres (we need more)
              cytoplasm? (does it devide? or just devide from 1 to 4? oh btw, if telophase doesnt occur in an oogonium——WHAT'S GONNA HAPPEN?= =| sperm comes into this big big cell, which will devide into 4?!)
              


              IP属地:加拿大7楼2011-01-09 09:45
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