Identify the mitotic stage from the given features .
(i) Nuclear envelope degenerates completely .
(ii) Chromosomes are spread throughout the cytoplasm .
(iii) Fully formed spindle apparatus consists of fine fibres .

Options

A. Middle prophase
B. Telophase
C. Anaphase
D. Prometaphase

Answer

To identify the mitotic stage based on the given features, we will analyze each feature step by step:

1. **Nuclear Envelope Degenerates Completely**:
- During mitosis, the nuclear envelope breaks down to allow the chromosomes to interact with the spindle fibers. This event typically occurs during the pro-metaphase stage of mitosis.

2. **Chromosomes are Spread Throughout the Cytoplasm**:
- In pro-metaphase, the chromosomes are not yet aligned at the metaphase plate; instead, they are dispersed throughout the cytoplasm. This is a characteristic feature of pro-metaphase, where chromosomes are still in the process of moving towards the center of the cell.

3. **Fully Formed Spindle Apparatus Consists of Fine Fibers**:
- The spindle apparatus is responsible for separating the chromosomes during mitosis. In pro-metaphase, the spindle fibers are fully formed and attach to the kinetochores of the chromosomes, which allows for their movement.

Based on the analysis of the features provided:

- The nuclear envelope degenerates completely in pro-metaphase.
- Chromosomes are spread throughout the cytoplasm in pro-metaphase.
- The spindle apparatus is fully formed and consists of fine fibers in pro-metaphase.

Thus, the correct answer is **Pro-Metaphase**.