Structural Organisation in Animals

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Colour: Brown or black. Bright yellow, red & green coloured cockroaches

are also seen in tropical regions.

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Size: 1/4 inches to 3 inches (0.6-7.6 cm).

Systematic position

Phylum

Class

Genus

Species

Arthropoda

Insecta

Periplaneta

americana

MØRPHØLØGÝ ØF ÇØÇKRØÅÇH

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The adults are about 34-53 mm long.

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Body is covered by a hard brown chitinous exoskeleton.

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In each segment, exoskeleton has hardened plates called sclerites

(dorsal tergites & ventral sternites). They are joined to each other by a

thin and flexible articular membrane (arthrodial membrane).

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The body has 3 regions – head, thorax and abdomen.

ËXTËRÑÅL FËÅTÜRËS ØF ÇØÇKRØÅÇH

Head

Tegmina

Hind Wing

Metathorax

Adbomen

Anal Cerci

Antennae

Compound Eye

Pronotum

Mesothorax

Prothoracic Leg

Mesothoracic Leg

Metathoracic Leg

HEAD

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Triangular head is formed by 6 fused segments.

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It shows great mobility in all directions due to flexible neck.

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Head bears a pair of thread-like antennae, a pair of compound

eyes and biting & chewing type mouth parts.

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Mouth parts: a labrum (upper lip), 2 mandibles, 2 maxillae,

hypopharynx (tongue) & a labium (lower lip).