Question

Draw a quick sketch of mitosis next to meiosis I and meiosis II. You can do it on paper, or on your screen if you have a touchscreen. Compare and contrast them to highlight 3 similarities and 3 differences. Make sure your diagram is CLEARLY labeled

Now draw meiosis with a cell that is diploid and has 3 different sets of chromosomes (that means there is a chromosome 1, 2, and 3, with 2 copies of each). Make sure that chromosomes 1, 2, and 3 are visually distinct

: Draw a sketch of meiosis but add a nondisjunction event to it (you can pick meiosis I or II). For each final daughter cell, CLEARLY identify whether there are any issues with it – does it have the correct set of chromosomes? If it was combined with another gamete to create a zygote, will the resulting zygote have too many or too few chromosomes? Is it missing any chromosomes completely?

How do I do this> what should I model this after?

Answer 1

- Draw a quick sketch of mitosis next to meiosis I and meiosis II. You can do it on paper, or on your screen if you have a touchscreen. Compare and contrast them to highlight 3 similarities and 3 differences. Make sure your diagram is CLEARLY labeled

Okay, let us make our drawing, remember that meiosis will segreggate both sister chromatides and homologous chromosomes, while mitosis will only segregate the chromatides:

Now let us list the differences:

1.- Meiosis includes a recombination event, mitosis does not

2.- Meiosis segregates the homologous chromosomes, mitosis does not

3.- Meiosis has 2 divisions, mitosis only one

Now the similarities:

1.- Both require DNA to be previously replicated

2.- Both segregate the sister chromatides

3.- Both of them use the cytoskeleton in order to segregate the chromosomes

- Now draw meiosis with a cell that is diploid and has 3 different sets of chromosomes (that means there is a chromosome 1, 2, and 3, with 2 copies of each). Make sure that chromosomes 1, 2, and 3 are visually distinct

We have to the same as in the previous image but now we are going to include 3 pairs of chromosomes (we used only one pair in the last one):

- Draw a sketch of meiosis but add a nondisjunction event to it (you can pick meiosis I or II). For each final daughter cell, CLEARLY identify whether there are any issues with it – does it have the correct set of chromosomes? If it was combined with another gamete to create a zygote, will the resulting zygote have too many or too few chromosomes? Is it missing any chromosomes completely?

Now let us use the same previous drawing but now we are going to add a non disjunction event in one of the cells in meiosis I:

Note that the result of this nondisjunction creates 2 gametes with 2 copies of a chromosome and 2 gametes with no copy of such chromosome, the first two gametes will create a zygote with a trisomy, and the last 2 gametes will create a zygote with a monosomy