Question

How many hearts does an earthworm possess?
A. 6 pairs
B. 5 pairs
C. 2 pairs
D. 1

Answer 1

Hint: Earthworm is a worm, which means it doesn't have a true heart but they have aortic arches, which connect ventral and dorsal vessels and pump the blood.

Complete answer:
In this question we have asked about the no. of hearts present in earthworm. An earthworm is a terrestrial invertebrate and we know that invertebrates have an open circulatory system and do not have a heart. But, in earthworms a closed circulatory system is present. Earthworms have three main vessels in them which circulate the blood. These vessels are: Aortic arches, ventral blood vessels and dorsal blood vessels. These aortic arches work like a human heart as they connect dorsal vessels to ventral vessels and pump the blood throughout the body. The dorsal blood vessels carry blood to the front of the earthworm’s body and the ventral blood vessels carry blood to the back of the earthworm’s body. The 4th, 5thand 6th segments of earthworm contain the blood glands. There are 10 aortic arches present in the earthworm or we can say 5 pairs of aortic arches are present in the earthworm.

So, the answer is B. 5 pairs.

Note:
The no. of heart in earthworm can be 0 or 10 depending upon the question and options, if they are asking about true heart, then earthworm have 0 heart and if they are asking about false heart then they have 10 hearts.