Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false
(e) If the assertion is false but reason is true
Assertion : Heart of fish contains only deoxygenated blood.
Reason : Oxygenated blood do not return back to the heart in fishes.

Answer

A

Explanation

The heart is a pumping organ for blood circulation which consists of chambers communicating with each other. In fishes the heart is two-chambered, consisting of an auricle and a ventricle. An accessory chambe called sinus venosus is also present which serves as a reservoir and opens anteriorly into auricle through the sino- atrial aperture. Fish heart contains and pump only deoxygenated blood because after getting oxygenated from gills, the blood doesn't return back to the heart. Instead. It is supplied directly to the various parts ot the body.