Homozygous: this means that the man has two genes for unattached earlobes, so whichever of these gene genes is transmitted to the child, it will be unattached. Since having unattached earlobes is a result of a dominant gene, one such gene is enough and the child will definitely have an unattached earlobe.
The answer is all of these occur. The tetrads need to be made before crossing over occurs, which only occurs in prophase 1. That automatically means it has to be all of the above.
