Q: 120 (IAS/1994)
question_subject:
Science
question_exam:
IAS
stats:
0,39,97,17,15,65,39
keywords:
{'haemoglobin': [10, 1, 0, 2], 'plasma': [5, 1, 1, 6], 'earthworm': [4, 0, 1, 0], 'frog': [11, 1, 6, 0], 'fish': [1, 2, 0, 0]}
The correct answer is earthworm because haemoglobin is dissolved directly in their blood plasma, not contained in red blood cells as in vertebrates such as in humans (option-3), frogs (option-1) and fish (option-2). Humans, frogs, and fish all have closed circulatory systems where haemoglobin is contained within the red blood cells. In contrast, earthworms have an open circulatory system where haemoglobin is dissolved directly in their blood plasma allowing it to deliver oxygen to their cells. Also, unlike vertebrates, earthworm`s haemoglobin is used for both oxygen transport and storage. This open circulatory system is common in invertebrates, allowing them to carry more oxygen in their blood than if it was enclosed in blood cells only.