12 slides

1 - Leptotene, the chromosomes appear as fine threads
2 - Zygotene, the homologous chromosomes associate in pairs. The chromosomes appear as strings of beads
3 - Pachytene, complete pairing of the chromosomes
4 - Diplotene, shortening of the chromosomes by contraction. Interchange of chromatin between the maternal and paternal chromosomes (crossing over)
5 - Diakinesis, further contraction of the bivalents, the nuclear membrane disappears
6 - Metaphase and anaphase of the first (heterotypic) division, showing spindle threads. Two haploid sets of chromosomes are separated
7 - Telophase of the first and prophase of the second division
8 - Metaphase and anaphase of the second (homeotypic) division, two mitotic figures are present
9 - Pollen tetrads, four nuclei are formed after the second division, each bearing the haploid number of chromosomes. Formation of cell walls
10 - Uninucleate microspores after separation of daughter cells
11 - Mature two-nucleate pollen grains at the time of shedding. Each pollen grain possesses a tube cell and a generative cell
12 - Mature pollen grains, w.m. to show structure of the cell walls