The metaphase plate present in meiosis I is shown above to the left and the metaphase plate present at mitosis is shown above to the right. As the picture shows, in meiosis, each INDIVIDUAL chromosome is only attached to ONE microtubule and one pole of the cell (monopolar attachment); this is because the other chromosome acts as the second spindle at regions where the two crossover (also known as chiasmata). On the other hand, there is no crossing over in mitosis, and thus, you need each chromosome to be attached to the microtubules from BOTH ends (which is referred to as bipolar attachment). Again, this question just comes down to understanding that tetrads (the combination of homologous chromosomes) -alongside the occurrence of crossing over –  are formed in meiosis, and for that reason, you get monopolar attachment rather than bipolar attachment.