When a vein,instead of carrying blood directly into the heart,first carries it to an intermediate organ like the liver,it is known as:

Given below are two statements regarding the circulation of blood in fishes.
Statement $I$: The heart of a fish contains only deoxygenated blood.
Statement $II$: Fishes show single circulation,and blood passes through the heart only once during each cycle.
In light of the above statements,choose the correct answer from the options given below.

Give information about open and closed types of circulatory pathways.

In which of the following is the right systemic arch absent?

Which of the following is the correct pathway for pulmonary circulation?

In which of the following is a single circulation of blood observed?