Mognadsdelning i pollenmodercellerna hos liljan (Lilium candidum) (12 bilder)

Prepared Microscope Slides

Basic component of the program are the A, B, C and D series comprising of 175 microscope slides. The four series are arranged systematically and constructively compiled, so that each enlarges the subject line of the proceeding one. They contain slides of typical micro-organisms, of cell division and of embryonic developments as well as of tissues and organs of plants, animals and man. Each of the slides has been carefully selected on the basis of its instructional value. LIEDER prepared microscope slides are made in our laboratories under scientific control. They are the product of long experience in all spheres of preparation techniques. Microtome sections are cut by highly skilled staff, cutting technique and thickness of the sections are adjusted to the objects. Out of the large number of staining techniques we select those ensuring a clear and distinct differentiation of the important structures combined with best permanency of the staining. Generally, these are complicated multicolor stainings. LIEDER prepared microscope slides are delivered on best glasses with ground edges of the size 26 x 76 mm (1 x 3"). – Every prepared microscope slide is unique and individually crafted by our well-trained technicians under rigorous scientific control. We therefore wish to point out thatdelivered products may differ from the pictures in this catalog due to natural variation of the basic raw materials and applied preparation and staining methods.

The number of series in hand should correspond approximately to the number of microscopes to allow several students to examine the same prepared microscope slides at the same time. For this reason all slides out of the series can be ordered individually also. So, important microscope slides can be supplied for all students.

Development of the Microspore Mother Cells - of Lilium candidum

12 Microscope 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