3B Scientific Cell Division II Chart, Meiosis - Manual (Page 4)

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English
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Meiosis
Interkinesis
Second meiotic division:
• Prophase II
• Metaphase II
• Anaphase II
• Telophase II
• Cytokinesis II
The 3B Scientific® model series on meiosis (product no. R02) and the wall chart on meiosis (V2051M,
V2051U) show a typical mammal cell at an enlargement of approx. 10,000 times. In the lower third
of the models/illustrations the cell organelles are portrayed open.
The 3B Scientific® model series on meiosis is supplied in a storage system, which is equipped with a
hanging device. The model series can thus be simply hung on a wall in order to save space. The models
also have magnets at the rear so that they can be arranged on magnetic boards in the classroom for tea-
ching purposes.
At the end of this description you will find illustrations of the 10 phases included. You can use these to
make photocopies for your lessons. By colouring, labelling and correctly arranging the individual phases
your students can easily review and memorize what they have learned.
Free colour illustrations of the individual stages are also available on the Internet at www.3bscientific.com.
1. Interphase, stage of the G
1
phase
Inside the cell the nucleus with the nucleolus (1) and its nuclear membrane (2) can be seen. The nucleus
also contains the not yet helical DNA (3) with the genetic information.
The cell itself receives its stability and shape from very fine tubes, the so-called microtubules (4) extending
through the cytoplasm. The microtubules control, among other things, the cell movements and the intra-
cellular transport processes.
In the cytoplasm, the endoplasmic reticulum (5) can be seen. This is an intertwined tube system mainly in
charge of lipid synthesis, ion storage and redesigning and transporting certain proteins. The membrane of
the rough endoplasmic reticulum has ribosomes attached to it, which synthesize the proteins passing
through the endoplasmic reticulum.
The Golgi complex (or apparatus) (6) can also be referred to as “cell gland”. It is made up of stacks of
layered hollow sacs (Golgi cisternae), which swell up as the vesicles become too small and “pinch off”
(Golgi vesicles) (7). The Golgi complex receives membrane components and enzymes from the endoplasmic
reticulum. Its main function is collecting, packing and transporting secretions and producing lysosomes
(digestion vesicles) (8).
The main job of the lysosomes is breaking down cell components (= intracellular digestion).
The mitochondria (9) are in charge of producing energy for the cell.
The job of the centrioles (10) is to build up the cleavage spindle. They are hollow cylinders made up of
longitudinally arranged tubes (microtubules).
2. Prophase I
The prophase of the first meiotic division is the part of meiosis that takes longest. In the course of this
phase, chromosomes and chromatin change their structure and arrangement within the nucleus in a