Question

Which of the following cellular structures always disappears during mitosis and meiosis?

• A. Plastid and nuclear membrane
• B. Nucleolus and nuclear membrane
• C. Endoplasmic reticulum and mitochondria
• D. Endoplasmic reticulum and plasma membrane

Answer 1

The correct option is B Nucleolus and nuclear membrane

Nucleolus and nuclear membrane always disappears during mitosis and meiosis. At the beginning of mitosis, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down, resulting in the release of most of the contents of the nucleus into the cytoplasm. At the end of mitosis, the process is reversed. In diakinesis stage of prophase I of meiosis I, nucleolus and nuclear membrane disappear and chromosomes set free in the cytoplasm.