Ladder pattern of DNA electrophoresis in apoptosis is caused by the action of following enzyme
**Core Concept**
The ladder pattern of DNA electrophoresis in apoptosis is a result of the fragmentation of DNA into regular sized pieces, which is a hallmark of programmed cell death. This process involves the activation of specific enzymes that cleave DNA at regular intervals. The underlying principle being tested is the biochemical mechanism of apoptosis, specifically the role of enzymes in DNA fragmentation.
**Why the Correct Answer is Right**
The correct answer is related to the enzyme responsible for the cleavage of DNA into regular sized fragments, resulting in the characteristic ladder pattern on DNA electrophoresis. This enzyme is caspase-activated deoxyribonuclease (CAD), also known as DNA fragmentation factor (DFF40). CAD is a crucial mediator of DNA fragmentation during apoptosis, and its activation leads to the cleavage of DNA at regular intervals, resulting in the ladder pattern.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not correspond to the correct enzyme involved in DNA fragmentation during apoptosis.
**Option B:** This option is also incorrect as it does not relate to the specific enzyme responsible for the ladder pattern of DNA electrophoresis.
**Option C:** This option is incorrect as it is not associated with the biochemical mechanism of apoptosis and DNA fragmentation.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the ladder pattern of DNA electrophoresis is a characteristic feature of apoptosis, and the enzyme responsible for this pattern is caspase-activated deoxyribonuclease (CAD). This knowledge is essential for understanding the biochemical mechanisms of programmed cell death.
**Correct Answer:** D. Caspase-activated deoxyribonuclease (CAD)