Question

Can anybody answer this
Q. 16

Answer 1

a)

b) because true that the oxygen and deoxygenated blood cannot be mixed up

c) Atria-carry the oxygen rich blood

Vein-carry the dii oxygen rich blood means carbon dioxide

Answer 2

2. It is necessary in mammals and birds to separate oxygenated and de-oxygenated blood because this makes their circulatory system is more efficient and helps in maintaining constant body temperature.

3. Arteries have thick walls while Veins have thin walls.