Chromosomes exchange genetic material in step 3.
<h3><u>Explanation</u>:</h3>
The meiosis is the type of cell division that takes place for gametogenesis. The meiosis has two phases - meiosis I and meiosis II.
The meiosis I has the events like crossing over and independent assortment which leads to the mixing of genes between homologous chromosome pairs and separation of homologous chromosome pairs. So the two cells that are produced from the meiosis I are genetically different. The step 3 shows the crossing over of prophase 1 of meiosis I. So, it shows the genetic difference between the offsprings and leads to genetic variation.
14 should be B if I can remember correctly, 15 is C
I dont understand what you mean but importance wise the picture would be most impotant