Question

In cockroach, the ostia are found on either side of
(A) Tracheae
(B) Heart chambers
(C) Testes
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(D) Ommatidia​

Answer 1

The correct answer is option B.

In cockroach, the ostia are found on either side of heart chambers.

• The heart of a cockroach is 13 chambered.

• Apertures or valvular openings, namely ostia, are present in pairs at the posterior end of the heart chambers.

• This is important as it maintains the flow of blood in one direction, i.e. from the pericardium to the heart.

Answer 2

(B) Heart chambers

Explanation:

The heart of the Cockroach is made of 13 chambers. The hinder end of each chamber of cockroach's heart has a pair of minute, lateral and valvular openings called ostia, which allows the flow of blood from the pericardium into the heart only and not in reverse direction. Ostia are guarded by auricular valves which prevents this reverse flow of blood.