When exactly does Crossing-Over in Meiosis occur?

[Henry930821]

I found contradiction in answers given by CIE over just two variants in the SAME session of exam.

9700/41/O/N/10 - 9(a) marking scheme says it happens in Metaphase 1.
http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w10_ms_41.pdf

9700/43/O/N/10 - 9(a) marking scheme says it happens in Prophase 1.
http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w10_ms_43.pdf


So which now?

 

[panda222]

Prophase 1 of Meiosis, process is called synapsis. It most certainly doesn't take up place in Metaphase 1.

Independent assortment occurs in Metaphase 1. Both cause genetic variation. Hope that helps.

 

[Henry930821]

Thanks! Anymore inputs? =]

 

[OakMoon!]

Prophase I, for sure.

 

[babycry]

prophase 1..99.9 percent sure

 

[Nishii]

yup prophase I ! since metaphase consists of the bivalents joining randomly at the equator only!