Question
Biology Question on Structural Organisation of Animals and plants
Earthworm possesses hearts
A
6 pairs
B
4 pairs
C
2 pairs
D
1
Answer
4 pairs
Explanation
Solution
In each of the segments 7, 9, 12 and 13 is found a pair of large, thick, muscular and rhythmically contractile vertical vessels, called hearts. They pump blood from dorsal to ventral vessel, while flow in opposite direction is prevented by internal valves. Hearts of 7th and 9th segments connect dorsal and ventral vessels only and are called lateral hearts. Those of 12lh and 13,h segments connect both dorsal and supra- oesophageal vessels with ventral vessel, and are designated as latero-oesophageal hearts.