Study of Blastula

Experiment No :

Objective:  To study T.S. of Blastula through permanent slide.

Requirements:

1.    Permanent slide of Blastula
2.  Compound microscope

Procedure:

1. The slide of the T. S. of Blastula is fixed under the compound microscope.
2. The slide is observed under the low power of the microscope.
3. Then, the slide is observed under the high power of the microscope.

Observations & Comments:

•  It is a spherical mass of about 64 cells.
• It is composed of 2 parts: (I) an outer envelope of cells called the Trophoblast or Trophoectoderm and (II) inner cell mass or embryoblast
• There is a fluid filled cavity called Blastocoel.
• The inner cell mass is the precursor of the embryo.
• The side of the blastocyst to which the inner cell mass is attached is called the Embryonic or Animal pole, while the opposite side is called the Abembryonic or Vegetative pole.

Fig : T.S. of  Blastula

Precautions:

1. It  should be observed first under the low power and then the high power of the compound microscope.
2. The fine adjustment should be used while focussing the slide under the high power of the microscope.

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