Self Assessment Question # 3
for Lesson 4

by Dr Jamie Love © 2002 - 2010
Genetics Course

Assume an organism has 22 chromosomes as its diploid number.

I want you to follow thorough all these nuclear and cellular divisions by telling me:

A

  1. how many chromosomes will each nucleus have after mitosis and are the nuclei haploid, diploid or polyploid.
  2. how many chromosomes will the cell have after mitosis, but before cytokinesis, and is the cell haploid, diploid or polyploid.
  3. how many chromosomes will each cell have after cytokinesis, following mitosis, and are the cells haploid, diploid or polyploid.
B
  1. how many chromosomes will each nucleus have after meiosis I and are the nuclei haploid, diploid or polyploid. (Assume this meiosis I has a proper telophase I.)
  2. how many chromosomes will the cell have after meiosis I, but before cytokinesis, and is the cell haploid, diploid or polyploid.
  3. how many chromosomes will each cell have after cytokinesis, following meiosis I, and are the cells haploid, diploid or polyploid.
C
  1. how many chromosomes will each nucleus have after meiosis II, and are the nuclei haploid, diploid or polyploid.
  2. how many chromosomes will the cell have after meiosis II, but before cytokinesis, and is the cell haploid, diploid or polyploid.
  3. how many chromosomes will each cell have after cytokinesis, following meiosis II, and are the cells haploid, diploid or polyploid.

Yes, this is a long and difficult question but it is very important that you understand it and it's good practice!
It may help you to draw them out - not all the chromosomes , just keep track of their numbers in each nuclei and cell.

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