Question

Which of the following blood vessels in the circulatory system of frog has more deoxygenated blood?
A. Pulmonary artery
B. Precaval veins
C. Pulmocutaneous artery
D. Pulmocutaneous vein

Answer 1

Hint: The circulatory system of a frog is a closed system. The circulatory system consists of the heart, blood, and lymphatic vessels. Its function is to transport liquid and gaseous elements to the living functional tissues. It also brings away the liquids and gaseous waste of metabolism to organs of excretion.

Complete answer:
In frogs, blood vessels divide into pulmonary and cutaneous arteries and transport venous blood through pulmocutaneous arteries to the respiratory surfaces of the skin. The frog carries out the respiratory exchange of gases through the moist skin. The blood returned from the skin through the pulmocutaneous vein is rich in oxygen content. It arises from the truncus arteriosus and transports blood to respiratory surfaces of the skin, buccal cavity, and lungs.
So, the right answer is Option C (Pulmocutaneous Artery).

Additional Information:-
In frogs, the circulatory system is closed and it uses the pulmonary circulation and systemic circulation. The system has two main jobs. First, it transports blood with oxygen and nutrients to cells present all over the body. Second, it picks waste materials from the metabolic cells to be removed out of the body, and it takes the deoxygenated blood back to the lungs so it can regenerate. As a frog has a closed circulatory system, the blood and other fluids remain inside a set of blood vessels and are never released into the body cavity. Usually, the blood vessels vary in size, and oxygen and nutrients are exchanged between blood vessels and tissues throughout the tiniest ones. Also, frogs use a system known as double circulation which means that there are now two pathways, or circuits, for blood to move around the body. The first circuit of arteries takes blood from the heart to an oxygen source (lungs), and the second circuit takes blood from the heart to the rest of the body.

Note: Frogs are cold-blooded, which means that their body temperatures change accordingly with the temperature of their surroundings. When the temperature lowers down, some frogs dig burrows underground or in the mud at the bottom of ponds. They hibernate or sleep for months in these burrows until spring, and they are perfectly still and scarcely breathing.