Question

Single circulation i.e. blood flows through the heart only once during one cycle of passage through the body, is exhibited by

• A. Labeo, Chameleon, Salamander
• B. Hiipocampus, exocoetus and Anabas
• C. Hyla, Rana, Draco
• D. Whale, Dolphin, Turtle

Answer 1

The correct option is B

Hiipocampus, exocoetus and Anabas

The correct option is B.

Explanation of the correct option:

• A single circulatory system is present in organisms that possess a two-chambered heart. In the single circulation, blood is passed from hearts to gills. Then after purification, it is passed to the whole body.
• The animals contain two-chambered hearts have one auricle (receiving chamber) and one ventricle (pumping chamber).
• Fishes or member of the Pisces group contains a two-chambered heart and single circulation system.
• Hippocampus, Exocoetus and Anabas are members of the Pisces group, so they show the single circulation.

Explanation of the incorrect options:

Option A:

• In this option, Labeo is a member of the Pisces group, but chameleon salamanders are members of the reptile and amphibia groups, respectively. Amphibian and reptilian members possess a three-chambered heart. Single circulation is not observed in the organisms that possess a three-chambered heart.

Option C:

• In this option, Hyla and Rana belong to class amphibia, and Draco belongs to the reptile class. Amphibian and reptilian members contain three-chambered hearts. Organisms that possess a three-chambered heart do not show a three-chambered heart.

Option D:

• In this option, Whale and dolphin belong to the mammal class and contains a four-chambered heart. Turtle belongs to class reptiles. Single circulation is not shown by the organisms that show 3 and 4 chambered hearts.

Therefore, the single circulation is exhibited by Hippocampus, Exocoetus and Anabas.