Question

In which of the following vertebrate group/groups, the heart does not pump oxygenated blood to different parts of the body?

• A. Pisces and amphibians
• B. Amphibians and reptiles
  
• C. Amphibians only
• D. Pisces only

Answer 1

The correct option is D Pisces only

(d) Pisces only

Fish have a single circulatory pattern, wherein the blood passes through the heart only once during each complete circuit. Oxygen-deprived blood from the body tissues comes to the heart, from where it is pumped to the gills. The gaseous exchange happens within the gills and the oxygenated blood from the gills is circulated throughout the body.
On the other hand, in mammals, the deoxygenated blood enters the heart from where it is pumped into the lungs for oxygenation. The oxygenated blood returns to the heart from the lungs which have to be transported throughout the body.