Question

Select the correct sequence of organs in the alimentary canal of cockroach starting from mouth:

• A. Pharynx→ Oesophagus →Crop→ Gizzard → Ileum→ Colon→ Rectum
• B. Pharynx→ Oesophagus→ Gizzard →Crop→Ileum → Colon→ Rectum
• C. Pharynx→ Oesophagus → Gizzard → Ileum → Crop →Colon→ Rectum
• D. Pharynx →Oesophagus→ Ileum → Crop→ Gizzard→ Colon → Rectum

Answer 1

The Correct Option is A

The question asks for the correct sequence of organs in the alimentary canal of a cockroach, starting from the mouth.

The alimentary canal of a cockroach is a long tube divided into three main parts: the foregut, midgut, and hindgut. Here is a breakdown of the sequence:

1. Pharynx: The pharynx is the portion just after the mouth where food is taken in.
2. Oesophagus: After the pharynx, food travels through the oesophagus, a narrow tube.
3. Crop: Following the oesophagus, the crop serves as a storage organ where food is temporarily held.
4. Gizzard: After the crop, the gizzard comes next. It is a muscular organ that grinds the food, assisting in the digestion process.
5. Ileum: This is a part of the midgut where further digestion and nutrient absorption occurs.
6. Colon: The colon comes next in the hindgut, where feces are formed and water is absorbed.
7. Rectum: Finally, the rectum is the last part of the alimentary canal that stores feces before excretion.

Based on the structured parts and their specific roles in digestion, the correct sequence is:

Pharynx→ Oesophagus →Crop→ Gizzard → Ileum→ Colon→ Rectum

Explanation and Justification:

• Option 1: Pharynx→ Oesophagus →Crop→ Gizzard → Ileum→ Colon→ Rectum - This matches the correct anatomical sequence as described above.
• Option 2: Pharynx→ Oesophagus→ Gizzard →Crop→Ileum → Colon→ Rectum - Incorrect, as the crop comes before the gizzard.
• Option 3: Pharynx→ Oesophagus → Gizzard → Ileum → Crop →Colon→ Rectum - Incorrect, as the crop should be before the gizzard.
• Option 4: Pharynx →Oesophagus→ Ileum → Crop→ Gizzard→ Colon → Rectum - Incorrect, as the ileum does not come before crop and gizzard.

Therefore, the correct option is the first one: Pharynx→ Oesophagus →Crop→ Gizzard → Ileum→ Colon→ Rectum.