Which of the following statements are correct regarding the organelle, lysosome ?
I. It contains enzymes mostly active in acidic pH.
II. It is known as the suicidal bag .
III. These organelles are directly derived from the endoplasmic reticulum .
IV. It contains water , sap, excretory product and other materials not useful for the cell.
(a) I , II ,III and IV
(b) I and II only
(c) II and III only
(d) I, II and IV only

Options

A. I , II ,III and IV
B. I and II only
C. II and III only
D. I, II and IV only

Answer

To determine which statements regarding lysosomes are correct, let's analyze each statement one by one:

**Step 1: Analyze Statement I**
- **Statement I:** "It contains enzymes mostly active in acidic pH."
- **Explanation:** Lysosomes contain hydrolytic enzymes that are indeed most active in an acidic environment (pH around 4.5 to 5). This statement is **correct**.

**Step 2: Analyze Statement II**
- **Statement II:** "It is known as the suicidal bag."
- **Explanation:** Lysosomes are often referred to as "suicidal bags" because they can break down cellular components and are involved in autophagy and apoptosis (programmed cell death). This statement is **correct**.

**Step 3: Analyze Statement III**
- **Statement III:** "These organelles are directly derived from the endoplasmic reticulum."
- **Explanation:** Lysosomes are not directly derived from the endoplasmic reticulum (ER). They are formed from the Golgi apparatus and are part of the endomembrane system. Therefore, this statement is **incorrect**.

**Step 4: Analyze Statement IV**
- **Statement IV:** "It contains water, sap, excretory product and other materials not useful for the cell."
- **Explanation:** While lysosomes do contain some water and enzymes, they do not contain sap or excretory products. Their primary function is to digest and break down waste materials and cellular debris. Thus, this statement is **incorrect**.

**Conclusion:**
Based on the analysis:
- Correct statements: I and II
- Incorrect statements: III and IV

Therefore, the correct answer is **(b) I and II only**.

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