Q.Draw a neat labelled diagram of mouthparts of a cockroach.

The cockroach has biting-and-chewing mouthparts made of the labrum, a pair of mandibles, a pair of maxillae (with palps), the labium (with palps) and a central hypopharynx.

(Diagram: draw the mouthparts separated out and labelled - the labrum at the top; below it the pair of toothed mandibles; then the pair of maxillae, each showing cardo, stipes, lacinia, galea and the 5-segmented maxillary palp; the labium at the bottom showing submentum, mentum, prementum and the labial palps; and the median hypopharynx in the centre.)

The mouthparts of Periplaneta americana are of the BITING and CHEWING (mandibulate) type, consisting of:

1. Labrum (upper lip):

• A broad flap forming the upper covering of the mouth; helps hold the food.

2. Mandibles (a pair):

• Hard, thick, jaw-like structures with toothed inner (grinding) margins; they cut and grind (masticate) the food, moving sideways.

3. Maxillae (a pair):

• Each consists of a basal cardo and stipes, bearing an inner toothed lacinia, an outer hood-like galea, and a 5-segmented MAXILLARY PALP.

• They hold the food, push it towards the mandibles and bear sensory palps for tasting.

4. Labium (lower lip): …

Cockroach mouthparts are of the biting-and-chewing type, made up of the labrum, a pair of mandibles, a pair of maxillae, the labium, and the hypopharynx.

Note: this answer describes and labels each part of the mouthparts in detail, since a hand-drawn figure cannot be rendered here - use this description to draw and label the diagram.

The mouthparts of Periplaneta americana (cockroach) lie in a ventral cavity called the gnathal/buccal cavity, bounded above by the clypeus and are of the primitive biting and chewing type. From outside inward, the parts are:

1. Labrum - a broad, flap-like structure attached to the clypeus, forming the upper lip; it covers the mouthparts from above and helps hold food in place during feeding.

2. Mandibles (a pair) - strong, dark-coloured, heavily sclerotised jaws lying just behind the labrum. Their inner (medial) edges bear cutting/crushing teeth, and they work side-to-side to bite and crush food.

3. Maxillae (a pair) - lie behind the mandibles; each maxilla consists of a basal cardo and stipes, which bear an inner toothed lacinia and an outer soft galea (both used to hold/manipulate food), plus a segmented, sensory maxillary palp (5-segmented) used to test/taste food.

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The cockroach has biting-and-chewing mouthparts made of the labrum, a pair of mandibles, a pair of maxillae (with palps), the labium (with palps) and a central hypopharynx.

(Diagram: draw the mouthparts separated out and labelled - the labrum at the top; below it the pair of toothed mandibles; then the pair of maxillae, each showing cardo, stipes, lacinia, galea and the 5-segmented maxillary palp; the labium at the bottom showing submentum, mentum, prementum and the labial palps; and the median hypopharynx in the centre.)

The mouthparts of Periplaneta americana are of the BITING and CHEWING (mandibulate) type. They consist of the following parts:

1. Labrum (upper lip):

• A broad flap that forms the upper covering of the mouth; it helps hold the food.

2. Mandibles (a pair):

• Hard, thick, jaw-like structures with toothed inner (grinding) margins; they cut and grind (masticate) the food. They move sideways.

3. Maxillae (a pair):

• Each maxilla consists of a basal cardo and stipes, bearing an inner lacinia (with teeth), an outer hood-like galea, and a 5-segmented MAXILLARY PALP.

• They hold the food, push it towards the mandibles and bear sensory palps for tasting.

4. Labium (lower lip): …

Cockroach mouthparts are hypognathous and of the primitive biting-chewing type, made up of the labrum, mandibles, maxillae, labium and hypopharynx, each with a specific role in seizing and processing food, as shown in the labelled diagram above.

Mouthparts of the cockroach (Periplaneta americana) — biting and chewing type, hypognathous (directed ventrally):

1. Labrum (upper lip): A broad, flap-like structure attached to the clypeus, forming the anterior/upper boundary of the mouth; it helps hold food in place during feeding.
2. Mandibles (a pair): Strong, heavily sclerotised, dark, triangular jaws with toothed/serrated inner (chewing) margins; they are the principal organs for biting and crushing/grinding food, moving side to side (unlike vertical jaws).
3. Maxillae (a pair): Located just behind the mandibles, each maxilla is a jointed appendage bearing:
   • Cardo and Stipes — basal segments attaching the maxilla to the head.
   • Galea — an outer soft, hood-like lobe.
   • Lacinia — an inner, more sclerotised, spine-tipped lobe used to hold and manipulate food.
   • Maxillary palp — a long, segmented (5-segmented), sensory feeler used for tasting/testing food.
4. Labium (lower lip): Formed by the fusion of the second (posterior) pair of maxillae; it forms the floor of the mouth and bears a pair of segmented labial palps (sensory) plus lobes (glossae and paraglossae) that help manipulate food. …