Which one of the following is one of the paths followed by `air//O_(2)` during respiraton in an adult male Periplaneta americana as it enters the animal body.

Options

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

Answer

A

Explanation

The respiratory system consists of spiracles that are present on the lateral sides of the body. The opening of spiracles is also regulated by sphincter which then passes to network of elastic, closed and branching air tubes called tracheae which divide into fine branches called tracheoles.