Meiosis and chromosome help...Please?!?!?

[Beth]

This activity could decide wether i get an A or a B in my Biology class. I need to make sure i get this right. if you coud help i would really appreciate it.

I have a paper that looks exactly like this:
http://i37.photobucket.com/albums/e76/elizabeth082/Meiosis.jpg
The directions are:
In large center circle sketch 2 pairs of homologous chromosomes as they would be positioned on the spindle equator on metaphase 1.

During anaphase 1, the pairs seperate. each chromosome of the pair moves toward closest pole.

in large center circle draw circle around the 2 chromosomes that are positioned above the equater and draw an arrow indicating towards upper pole

next draw circle around 2 chromosomes that are positioned below equater draw arrow to go to bottom pole

Sketch chromosomes as they would be positioned on the equater in metaphase 2, remembering that homologous pairs are no longer present and sister chromatids of each chromosomes lie on opposite sieds of the eequator.......

well this is what i have it looking like:
http://i37.photobucket.com/albums/e76/elizabeth082/Meiosisfinished.jpg

My major question is, i am not comprehending how to sketch them in on metaphase 1 and which 2 go to metaphase 2????

 

[Sam McShane]

OK, you got it pretty close, but you messed up a bit in metaphase 1.
In metaphase 1 the homologous pairs will line up. This means that aa will line up next to AA and ee next to EE like this (pretend there is a line between them)

aa AA
ee EE

then they will separate like this

aa<-- -->AA
ee<-- -->EE

This is how meiosis 2 should look

Cell 1

a<-- -->a
e<-- -->e

Cell 2

A<-- -->A
E<-- -->E

At the end you should have one gamete with e and a, another with e and a, one with A and E, and another with A and E.

the a's and e's represent different alleles for a single gene. You need one of each in each gamete or else you'll be missing genes! not good.

I hope my diagrams make sense.