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Respiration and Circulation — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYRespiration and Circulation4 Marks
Question
Distinguish between : Single circulation and Double circulation.
✓

Answer

Single circulationDouble circulation
1. Blood flows only once through the heart in a complete cycle.1. Blood flows twice through the heart during one complete circulation. Systemic – to and fro ‘ from heart to body and pulmonary – to and fro from heart to lungs.
2. Heart pumps deoxygenated blood only.2. Heart pumps both deoxygenated and oxygenated blood to lungs and body respectively.
3. Blood is oxygenated in gills.3. Blood is oxygenated in lungs.
4. Occurs only in fishes.4. Occurs in amphibians, reptiles, birds and mammals.

 

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