Question

Directions: Choose the correct option:

Assertion $\left(A\right):$ Single circulation is seen in fishes.

Reason $\left(R\right):$ Only deoxygenated blood passes through it.

Answer 1

Correct option: $\left(b\right)$Both assertion$\left(A\right)$ and reason$\left(R\right)$ are true, but reason$\left(R\right)$ is not the correct explanation for assertion.

$\bullet$ In fishes, a two-chambered heart $\left(\text{one ventricle and one auricle}\right)$ is present.

$\bullet$ The whole circulatory system is a one-way arrangement, with the heart pumping only deoxygenated blood from the body forward to the gills to be oxygenated and redistributed to the body.

$\bullet$ So the correct option is $\left(b\right).$