Which of the following is correct about metaphase - I ?

Options

A. Bivalents are arranged at equator
B. Univalents are arranged at equator
C. Non-homologus chromosomes forms pair
D. Spindle fibers are attached at chromomere

Answer

To solve the question regarding what is correct about metaphase I, we can break down the information step by step:

### Step 1: Understand the context of Metaphase I
Metaphase I is a stage in meiosis, which is the process of cell division that reduces the chromosome number by half, resulting in the formation of gametes (sperm and eggs).

### Step 2: Identify what occurs during Metaphase I
During Metaphase I, homologous chromosomes (each consisting of two sister chromatids) align at the equatorial plane of the cell. These paired homologous chromosomes are referred to as bivalents or tetrads.

### Step 3: Analyze the options provided
1. **Bivalent arranged at the equator**: This option states that bivalents are arranged at the equator, which is true. This is the defining characteristic of Metaphase I.
2. **Univalents are arranged at the equator**: This option is incorrect because univalents (single chromosomes) do not align at the equator during Metaphase I; it is the bivalents that do.
3. **Non-homologous chromosomes form pairs**: This option is also incorrect. In Metaphase I, it is homologous chromosomes that pair, not non-homologous chromosomes.
4. **Spindle fibers are attached at the chromosome**: While spindle fibers do attach to chromosomes, this statement is misleading in the context of Metaphase I, as the attachment occurs more prominently in Metaphase II.

### Step 4: Conclusion
Based on the analysis, the correct statement about Metaphase I is that "bivalents are arranged at the equator."

### Final Answer
The correct option is: **Bivalent arranged at the equator.**

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