Question

Which one of the following is one of the paths followed by air or O2 during respiration in the adult male Periplaneta americana as it enters the animal body?

• A. Spiracle in metathorax, trachea, tracheloes, oxygen diffuses into cells
• B. Mouth, bronchial tube, trachea, oxygen enters cells
• C. Spiracles in prothorax, tracheole^, trachea, oxygen diffuses into cells.
• D. Hypopharynx, mouth, pharynx, trachea, tissues

Answer 1

The Correct Option is A

To determine the correct path of air (or oxygen) during respiration in the adult male Periplaneta americana (American cockroach), we need to understand the respiratory system of insects.

Insects, unlike humans, do not have lungs. They breathe through a network of small tubes called tracheae that deliver oxygen directly to their tissues.

Let's evaluate each option:

1. Spiracle in metathorax, trachea, tracheloes, oxygen diffuses into cells: This is the correct path. The air enters through the spiracles (openings in the insect's body), specifically those located in the metathorax. It then travels through the trachea, which branches into finer tubes called tracheoles. Finally, oxygen diffuses into the cells.
2. Mouth, bronchial tube, trachea, oxygen enters cells: This description is incorrect for insects. They do not breathe through their mouths nor have bronchial tubes.
3. Spiracles in prothorax, tracheole^, trachea, oxygen diffuses into cells: This path incorrectly suggests a sequence. Air travels from spiracles to trachea to tracheoles, not vice versa.
4. Hypopharynx, mouth, pharynx, trachea, tissues: Insects do not use these structures for respiration. These are parts of the digestive system in insects.

Based on this analysis, the correct answer is: Spiracle in metathorax, trachea, tracheloes, oxygen diffuses into cells.