Question

what is single circulation and double circulation ?​

Answer 1

Answer:

Figure 7.2: Single circulation system as found in a typical fish species. The red represents oxygen-rich or oxygenated blood, the blue represents oxygen-deficient or deoxygenated blood. Double circulation pathways are found in birds and mammals. Animals with this type of circulatory system have a four-chambered heart

Explanation:

Answer 2

Answer:

single circulation is when the blood goes through the heart once during its cycle through the body. it mainly happens in fishes.

double circulation is the circulation of blood twice through the heart. mainly happens in vertebrates

here the blood brings back deoxygenated blood from rest of the body into the heart. the heart pumps it to the lungs. this is the first time it enters the heart. then blood brings oxygenated blood from the lungs to the heart. this is the second time it enters it and the heart pumps it to the rest of the body.