Page 194 - Biology_F5

Comparative studies of natural groups of organisms

(g) Carefully lift the last abdominal (i) Remove fats to expose the gut and
tergum using a forcep, then cut one other organs in the body cavity.
side of the abdomen. Work forward by (j) Cover your dissection with water to
lifting aside the terga with forceps and bring the organs float up, prevent them
cut around the edge with small scissor from drying up and to enable them
or scalpel up to the base of the head being seen clearly.
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(Figure 3.58a).
(k) Loosen the gut, deflect to one side and
(h) Place a pin to hold the terga aside (you pin it to display all the systems (Figure
can use an optical pin to clearly pin it 3.59).
and ease observation of all parts in the
terga as well as those of the abdominal
cavity (Figure 3.58b).

Salivary
gland
Receptacle
Oesophagus
Crop

Gizzard

Hepatic digestive caeca
Mesenteron
Colon
Rectum
Malphighian tubule
Ileum
Anal cercus

Figure 3.59: General view of the dissected cockroach

(l) Make sure the body wall is neatly Safety precautions
pinned aside, the dissection is generally 1. Care should be taken when working
neat with all required features; avoid with live specimens and apparatus,
damaging the organs and blocking the including dissection kit tools.
ducts.
2. The working area, equipment and
(m) Carefully examine all internal parts instruments used must be thoroughly
using a hand lens.
cleaned and decontaminated after
use, by using appropriate methods.

3. Good hygiene practices should be
observed all the time; hands should be
kept away from the mouth, nose, eyes,

Form Five Student’s Book
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