lecture recording on 21 February 2025 at 13.57.06 PM
Overview of Mitosis
Mitosis: Process of genetic material division, also known as cell division. Focuses on the division of genetic material, excluding cytoplasmic components.
Stages of Mitosis
Mitosis consists of four stages:
Prophase
Metaphase
Anaphase
Telophase
Interphase: Non-mitotic stage where the cell performs regular functions, consisting of Gap 1, Synthesis, and Gap 2.
Prophase
Chromatin Condensation: Chromatin folds to form visible chromosomes.
Nuclear Envelope Breakdown: The membrane separating the nucleus from cytoplasm disintegrates, allowing genetic material to be accessed.
Spindle Formation:
Spindle apparatus, made of microtubules, begins to form and attaches to chromosomes.
Centrioles: Organizing structures located at opposite poles of the cell in animal cells; absent in plant cells (plant cells use microtubule organizing centers).
Metaphase
Chromosomes align at the cell's equatorial plane due to equal tension exerted by spindle fibers.
Anaphase
Sister chromatids are pulled apart by the spindle fibers, now considered as individual chromosomes, moving towards opposite poles of the cell.
Telophase
Decompaction of Chromosomes: Chromosomes begin to unwind back into chromatin.
Nuclear Envelope Reforms: Newly formed nuclei emerge around the chromatin.
Spindle Disassembly: The spindle apparatus is dismantled.
Cytokinesis: Physical division of the cytoplasm occurs, pinching off to form two separate daughter cells.
Differences in Plant Cells
In plant cells, cytokinesis involves the formation of a new cell wall between the two daughter cells, in addition to the plasma membranes.