Question

When a frog's heart is removed from its body, it continues to beat for some time.

Choose the most appropriate option from the following statements.

• A. Only (c)
• B. Only (d)
• C. (a) & (b)
• D. (c) & (d)

Answer 1

The correct option is D

(c) & (d)

The correct option is D.

Explanation for correct option:

1. A Frog's heart is a three-chambered heart with two atria and one ventricle.
2. The term "myogenic heart" refers to a heart that is always contracting in a rhythmic pattern.
3. The heart of a frog has specialized muscles (the sino-auricular node) to send out an impulse that causes it to contract.
4. So, the frog's heart is referred to as the Myogenic heart.
5. The frog's heart is independent of the neurological system to excite itself.
6. So, the frog's heart is autoexcitable.
7. As a result, it continues to beat even after it has been removed from the body for some time.

Explanation for incorrect options:

Option A:

1. The heart of the frog is both myogenic in nature and also autoexcitable.
2. Although statement (c) is correct. But the best option is D mentioning both statements (c) and (d) are correct.

Option B:

1. The heart of a frog is not only autoexcitable but also myogenic in nature.
2. Thus, it is an incorrect option.

Option C:

1. A Frog is a poikilotherm but this feature of the frog helps in changing the temperature of a body according to its surrounding.
2. So that frogs can survive in an unfavorable environment.
3. But this feature is not related to the heart.
4. Coronary circulation is the flow of blood through the blood arteries that provide the heart muscles with oxygen and nutrients.
5. But when a heart is removed from its body as the blood veins get separated from the heart, blood flow becomes impossible.
6. So, both statements (a) and (b) are not correct.

Final Answer: When a frog's heart is removed from its body, it continues to beat for some time as the heart of a frog is myogenic in nature and also autoexcitable.