Mark the correct description of circulatory system in Pheretima. - Sri Chaitanya Infinity Learn Best Online Courses for NCERT Solutions, CBSE, ICSE, JEE, NEET, Olympiad and Class 6 to 12

A
Open circulatory system with a 13-chambered heart.
B
Closed circulatory system with four pairs of anterior loops.
C
Closed circulatory system with four pairs of hearts.
D
Closed circulatory system with two major dorsal blood vessels.

Solution:

Pheretima has a closed blood vascular system. It has two major blood vessels-dorsal and ventral. These two are connected by 4 pairs of hearts present in 7^th, 9^th, 12^th, and 13^th segments. Each segment contains one pair of hearts. Lateral hearts are present in 7^th and 9^th segments. Lateral oesophageal hearts are present in 12^th and 13^th segments.

One pair of anterior loops are located in each of 10^th and 11^th segments.