Question

explain centriole,mitotic spindle, microtubles,cromatids-with diagram

Answer 1

• Centrioles are the organelles found in the animal cells. They have a crucial role during the cell division (You may have studied about mitosis and meiosis). During these processes of cell division they are involved in the formation of a thread like structures called spindle fibers. During cell division, the single parent cell divides itself into two daughter cells, and the spindle is responsible for separating or pulling the duplicate chromosomes to the two daughter cells.
• We can simply define Centrioles as a ' The paired cylindrical organelles located near the nucleus which play an important role in the cell division.'
• Spindle fibres are collectively known as mitotic spindle . Between the separating asters, spindle shaped fibres develops outside the nucleus during mitosis. The fibres that constitute the mitotic spindle, pull the chromatids apart toward opposite poles.
• Microtubules are tiny sub component of the cytoskeleton, found throughout the cytoplasm. Centrioles migrate in pairs to the opposite ends of the cell. Short radiating microtubules assemble around them. These microtubules surrounding each pair of centrioles, look like a start shaped body called aster. They also known as astral rays. They maintain the cell structure and involved in cell division.
• Chromatids are each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.