TRICHOCYSTS,NUCLEUS-PARAMECIUM

TRICHOCYSTS-The trichocysts first seen in paramecium in by  Elis.It is rod like structure or oval organelles present through out the ectoplasm alternating with basal bodies and oriented at the right angles to the body surface.These small in size .It consist of elongated shaft and a terminal pointed tip called the spike or barb covered by a cap.The matrix of the shaft consist of a dense mass  of a fibrous protein called as 'trichinin'.The main function of trichocysts is to anchor the animal to a firm substratum when it feeds upon bacteria.It occur in a span of a few milli seconds.when fully discharged the shaft becomes a long cross-straites rod and measures about 40 mew in length.
NUCLEUS-Thereis two type of nucleus present in paramecium.It is heterokaryotic in nature.In p.caudatum there is a large macronucleus and a small micronucleus.The macronucleus is roughly kidney-shaped with inconspicuous nuclear membrane.It is polyploid and posses many nucleoli and much chromatin material.
MACRONUCLEUS-It is somatic or vegetative nucleus and controls the day to day metabolic activites of the cell.It is derived from micronucleus during reproductive processes.
MICRONUCLEUS-It is a depression like structure on the surface of the macronucleus.It is usually spherical and with a nuclear membrane and diploid number of chromosomes.It control the reproductive activities of the organisms.