Why the two sides of the heart are kept separate; double circulation
The same question, asked 3 times: 2023*, 2025*, 2026. Every wording below, oldest first.
Try each one first, then open its answer.
Question 1
2023
29 (B)(i) What is double circulation ? (ii) Why is the separation of the right side and the left side of the heart useful ? How does it help birds and mammals ?Question 2
2023
22(a) Why is it important to prevent oxygenated and deoxygenated blood from mixing in birds and mammals ? (b) Which animals can tolerate some mixing of the oxygenated and deoxygenated blood streams ? On what factor does the body temperature of these animals depend ?Question 3
2025
29Why is blood circulation in vertebrates known as “double circulation”? Trace its path in the form of a flow chart.Question 4
2026
12Separation of right side and left side of the heart is useful to keep oxygenated and deoxygenated blood from mixing. Various organisms have different types of heart. (I) Fill in the blanks (i) to (iii) correctly according to the type of organisms and their evolution in terms of blood circulation :(II) Which type of circulation is most efficient ?Organisms Number of chambers in heart Type of blood being circulated Type of circulation Fish (i) ______ Mixed Single (ii) ______ 3-chambered Mixed Incomplete double circulation Birds and Mammals 4-chambered Separated circulation path of oxygenated and deoxygenated blood (iii) ______