[Biology][Practical-13] Mitosis and Meiosis Final High Yield Questions

General Discussion
1

MITOSIS AND MEIOSIS

  • The spindle is a microtubule-based scaffold that ensures even chromosome distribution between daughter cells

  • Crossing over is the process that produces new and random combinations of genes through their exchange between 2 non-sister chromatids of homologous chromosomes. It happens during meiosis, and more precisely, during prophase.

  • Chromatin is the general packaging of DNA around histone proteins

  • Histone + protein = nucleosome helps condense DNA to fit within the cell’s nucleus

  • During metaphase, the nuclear membrane is completely disintegrated. The chromosomes align in the middle of the cell, to prepare for chromatid separation

  • Anaphase is the phase where the centromeres are split. Each half moves to opposite poles

  • At the beginning of mitosis, a chromosome consists of two sister chromatids

  • Chromatids are used to describe the chromosome in its duplicated form

  • Prophase is the first phase of mitosis. It is the phase during which the the nuclear membrane begins to disintegrate

  • Throughout most of the cell cycle, DNA is packaged in the form of chromatin

  • Telophase is the phase where the nuclear envelope reforms around the separated chromosomes

  • Centrioles are made of microtubules (a polymer of tubulin) and form the aster and spindle: they are fibers of microtubules that will split centromeres

  • The centromere is the area where the 2 sister chromatids of a chromosome are in contact

  • Chromatin exists in an organization known as a chromosome during mitosis and meiosis

  • Chromatids are used to describe the chromosome in its duplicated form

  • What are the different phases of mitosis?

  1. prophase
  2. metaphase
  3. anaphase
  4. telophase

  • Prophase is precedented by genetic replication during interphase

  • What is the number of chromosomes during metaphase? 46

  • What is the number of chromatids during telophase? 92

  • What is the number of chromatids and chromosomes at the end of mitosis? 46 and 46

  • A tetrad is 2 attached homologous chromosomes (4 chromatids)

  • What is the number of chromatids during telophase II of meiosis? 46

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Hello! Isn’t the number of chromatids 46? And after cytokinesis 23?

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We do have 46 at the end

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Hey Ari!

Could you please clarify the difference between: chromatin, euchromatin, heterochromatin and chromosome?

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Heterochromatin has condensed chromatin structure and is inactive for transcription, while euchromatin has loose chromatin structure and active for transcription.

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