**2. Discuss or diagram the path of blood flow through the heart, lungs, and body of a fish and that of a mammal.**When explaining the circulatory systems:**Fish Circulation:**- **Single Circulation System:** Blood passes through the heart once during each complete circuit. - **Path:** The heart pumps deoxygenated blood to the gills, where gas exchange occurs. Oxygenated blood then travels directly to the rest of the body and returns as deoxygenated blood to the heart.**Mammal Circulation:**- **Double Circulation System:** Blood passes through the heart twice during each circuit—once for systemic and once for pulmonary circulation.- **Pulmonary Circulation:** Deoxygenated blood moves from the right side of the heart to the lungs to receive oxygen and releases carbon dioxide.- **Systemic Circulation:** Oxygenated blood returns to the left side of the heart and is pumped to the rest of the body, supplying organs and tissues before returning as deoxygenated blood to the heart.For educational purposes, diagrams can enhance understanding by illustrating these circulatory pathways, highlighting the differences between fish and mammal systems.

The physical appearance of both including fish and mammals are different from each other , so will be their traits and the pathways of blood flow through heart , lungs and body .CIRCULATION IN MAMMALS ( humans ) : In mammals we usually observe double circulation , where the heart is present that is divided into two half parts - right and left . The right part usually helps in pumping deoxygenated blood to the lungs . The left part usually helps in pumping oxygenated blood to the body . It also has four chambers 2 atria and 2 ventricles . The deoxygenated blood is usually lo in oxygen comes from the right side of the heart receives blood back from the body . It then enters the right atrium and reaches the right ventricle that is pumped to the lungs where the blood is being oxygenated . The oxygenated blood from the lungs enters the left ventricle via the left atrium and flushed directly into larger parts of the body for circulation. CIRICULATION IN FISH : Fishes usually have GIILS as that of lungs in mammals (humans) , they usually have single circulation connected as in series arrangement . Its heart only has one article and one ventricle . The oxygen supply of the body usually travels from the body the enters atrium and ventricles . It is finally pumped out through gills and distributed evenly throughout the rest parts of the body.