Page 193 - Biology_F5

Biology for Advanced Level Secondary Schools

Dissection of the cockroach allows while the dorsal side (tergum) is facing
learning of the location and appearance upwards.
of internal organs; distinguishing among (e) Allow the wax to cool, and then the
different types of tissues within an insect insect will be fixed (Figure 3.57).
body and to describe the major body
systems. The following practical guidelines
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in dissecting a cockroach, permit the studies
of internal features of the insect, including
its heart, as well as circulatory, digestive and
reproductive systems. Materials necessary
for the dissection of a cockroach include
dissection kit, dissecting tray or board, a
piece of thread, dissecting pins or office
pins, scissors, fine-point forceps gloves
and chloroform.

General procedure for dissecting a
cockroach
(a) Melt little wax in the centre of
dissecting tray.
Figure 3.57: Cockroach fixed for dissection
(b) Wear a pair of gloves.
(f) Since cockroach’s heart is on its dorsal
(c) Cut the insect wings, antennae and legs
close to their base. side attached inside the terga and
nervous system is on its ventral side,
(d) Place the cockroach in the melted wax when dissecting, cut either on its left or
or use dissecting pins, to place the right lateral side (pleural) from the last
cockroach on its ventral side (sternum),
segment of the abdomen to the thorax.

(a) (b)

Figure 3.58: Fixed cockroach showing (a) lifted aside terga (b) pined terga

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