Read the following four statements (i -iv)
(i) Every chromosome essentially has a primary constriction or the centromere.
(ii) During different stages of cell division, cells show structured chromosomes in place of the nucleus .
(iii) Nuclear pores are the passages through which movement of RNA and Protein takes place in one direction between the nucleus and cytoplasm.
(iv) Chromatin contains DNA, some basic proteins called histone adn RNA only .
How many of the above statement are

Options

A. Four
B. One
C. Two
D. Three

Answer

To determine how many of the given statements are correct, let's analyze each statement one by one.

### Step 1: Analyze Statement (i)
**Statement (i):** Every chromosome essentially has a primary constriction or the centromere.
**Analysis:** This statement is correct. Every chromosome has a centromere, which is the region where the two sister chromatids are joined together. The centromere plays a crucial role during cell division.

### Step 2: Analyze Statement (ii)
**Statement (ii):** During different stages of cell division, cells show structured chromosomes in place of the nucleus.
**Analysis:** This statement is incorrect. During cell division, the chromatin condenses to form structured chromosomes, but the nucleus itself is not replaced; rather, it disintegrates during prophase and reforms after telophase.

### Step 3: Analyze Statement (iii)
**Statement (iii):** Nuclear pores are the passages through which movement of RNA and Protein takes place in one direction between the nucleus and cytoplasm.
**Analysis:** This statement is incorrect. Nuclear pores allow for the bidirectional movement of molecules, including RNA and proteins, between the nucleus and the cytoplasm.

### Step 4: Analyze Statement (iv)
**Statement (iv):** Chromatin contains DNA, some basic proteins called histone, and RNA only.
**Analysis:** This statement is correct. Chromatin is composed of DNA, histone proteins, and can also contain RNA, making this statement accurate.

### Summary of Findings
- **Correct Statements:** (i) and (iv)
- **Incorrect Statements:** (ii) and (iii)

### Conclusion
Out of the four statements, **2 statements are correct** (i and iv).

### Final Answer
The number of correct statements is **2**.

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