Which one of the following precedes re formation of the nuclear envelope during M phase of the cell cycle? (a) Decondensation from chromosomes, and reassembly of the nuclear lamina (b) Transcription from chromosomes, and reassembly of the nuclear lamina (c) Formation of the contractile ring, and formation of the phragmoplast (d) Formation of the contractile ring, and transcription from chromosomes
Option C M phase or mitotic phase is the actual division phase and formation of contractile ring and formation of phragmoplast precedes reformation of nuclear envelope. Contractile ring is beltlike bundle of actin and myosin that appears during cell division immediately below the plasma membrane. Contraction of this ring leads to the separation of the two daughter cells. Phragmoplast is the region of plant cell cytoplasm that becomes evident in the latter stages of mitosis. It forms from the residual microtubules of the polar mitotic spindle and appears to function in transporting materials to the new cell plate forming between the daughter cells. Once the cell plate is complete, the phragmoplast is divided and gradually disappears, the cell plate finally becoming transformed into the middle lamella lying between the new cell walls
