Chapter 32, Problem 1STP

Summary Introduction

Introduction:

Most reptiles contain a 3-chambered heart similar to that of the amphibian’s heart. The blood moves towards the pulmonary and systemic circuits where the oxygenated and deoxygenated blood are divided by a partial septum in the ventricle.

Answer to Problem 1STP

Correct answer:

The correct answer is option (b) double loop and three-chambered heart.

Explanation of Solution

Explanation/justification for the correct answer:

Option (b) the blood is pumped from a three-chambered heart that has two atria and a single ventricle. Reptiles got two circulatory routes in the blood where only the oxygenated blood moves through the lungs.

Explanation for incorrect answer:

Option (a) though the double loop is correct as the blood flow is directed in two circuits:

1. Through the lungs back to the heart which is called the pulmonary circulation.
2. Through the rest of the body including the brain.

But the four-chambered heart isn’t found in reptiles much except in crocodiles.

Option (c) single loop isn’t the correct option as the blood flow is directed in two circuits.

Though the three-chambered heart is correct in the case of maximum reptiles.

Option (d) single loop isn’t the correct option as the blood flow is directed in two circuits. Two chambered heart also isn’t found in reptiles.

Conclusion

The circulatory system of most reptile are double loop and three chambered heart.