NEET BIOLOGY

Detailed explanation-1: -The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.

Detailed explanation-2: -During prophase, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down.

Detailed explanation-3: -The nuclear envelope, including nuclear pore complexes, breaks down at the beginning of mitosis to accommodate the capture of massively condensed chromosomes by the spindle apparatus. At the end of mitosis, a nuclear envelope is newly formed around each set of segregating and de-condensing chromatin.

Detailed explanation-4: -In fission yeast, the nuclear envelope (NE) remains intact during mitosis and meiosis I but is compromised during meiosis II.

Detailed explanation-5: -In the context of the cell cycle, mitosis is the part of the division process in which the DNA of the cell’s nucleus is split into two equal sets of chromosomes.