Page 192 - Biology_F5

Comparative studies of natural groups of organisms

left phallomere (largest) and the ventral chamber. A genital pouch or gynatrium is
phallomere (smallest). These, together with divisible into a genital chamber in front and
the pseudo-penis, form the organ used to the oothecal chamber behind.
transfer the sperm pouch to the female
during copulation (Figure 3.55). Female gonapophyses consist of three pairs
of chitinous rods hanging from the roof
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Reproductive system of a female of the oothecal chamber into its cavity.
cockroach They help in shaping the ootheca and
The female organs consist of ovaries, depositing eggs in it. The ootheca of the
oviduct, vagina, genital chamber, cockroach contains sixteen fertilised eggs,
spermathecae, collateral glands, and female coated with the secretions (protein, and
gonapophyses (ovipositor processes). dihydroxyphenol) of the colleterial glands.
Ovaries of the cockroach are located
laterally in the abdominal segments four, The eggs are lying in two rows, each with
five and six. Each ovary consists of eight eight eggs. The female cockroach carries the
ovarioles (Figure 3.56). ootheca for several days and finally protrude
more and more until it is deposited to the

One oviduct from each side open into a dark crevice, and for about six weeks, the
genital chamber at a slit-like aperture. A pair young cockroaches hatch out and grows
of collateral glands also open in the genital into adult.

Ovaries

Filament

Egg chamber
Pedicel
Oviduct
Common oviduct
Left collateral Spermatheca
gland Right collateral gland
Genital chamber
Oothecal chambers

Figure 3.56: The reproductive system of a female cockroach

Dissection of a cockroach careful dissection or cutting apart of an
Animals are dissected to analyse the organism and on accurate descriptions of
structure and function of their body the body parts. Dissection involves attentive
components. Dissection provides crucial isolation and removal of individual organs,
opportunity for students and other scientists accessing the area in which the organs are
to develop observational skills. The methods situated, and systematically removing the
of investigating gross structure depend on anatomical connections of organ to its
surrounding.

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