Thursday, 8 July 2021

Mature segment contains well developed hermaphrodite

  Mature segment contains well developed hermaphrodite 

Taenia solium is found in the intestine of man. The scolex lies buried in the intestinal mucosa. Commonly called as Pork tapeworm. Scolex serves as hold-fast organ. It contains 4 suckers and a rounded rostellum. Suckers contain Rostellum at its base contains double row of 28 to 32 books. Neck region is area of proliferation. Mature segment contains well developed hermaphrodite genital organs.

Gravid segments contain Branched uterus filled with onchospheres Life-cycle includes two hosts (i) man as definitive host and (ii) pig as intermediate host. Logitudinal and transverse excretory canals are seen in all segments. In villages, man deficates in the open field. Pig eats contaminated human faeces containing onchospheres and becomes infected. 

Onchospheres or hexacanth larvae develop into Cysticerous larvae or bladder worm called as Cysticercus cellulose, which encyst in thigh, chest, shoulder muscles of the pig. Such muscle is called as meašly pork.

 When man eats inadequately cooked hot dog or measly pork, it becomes infected and Taenia solium develops into adult in the intestine. It causes various diseases in man like anaemia, secondary nausea and insomnia, etc. Upto 13% eosinophilia is caused by it. It also causes metabolic disturbances in the host. anaemia, eosinophilia, diarrhoea, haemrrhage, abdominal pain. 

 Annular in narrow and small protoxylem vessels

 Number of xylem bundles.  Xylem vessels are called oval or ts.  is rounded in.  Metaxylem vessels have thickened.  Narrow and small protoxylem vessels have annular, spiral, reticulate or scalariform thickenings.  Between the phloem and xylem bundles are one or more layers of conjugate tissue.  The conjunctival tissue in young roots is composed of parenchyma cells.

 In older roots the cells become so numerous that the vascular strands become embedded in sclerenchymatous cylinders.  Parenchymatous conjunctive tissue stores food and helps in its lateral conduction.  It provides mechanical strength to the old roots.

 This does not form a vascular cambium.  Pith: This occurs in the center of the root.  Pith is parenchymatous: cells are usually round or oval.  Small intercellular spaces are present.  Cells store food.  In monocot roots of drier regions, pith cells are thick-walled or flattened.

 Reasons for identification: (i) Presence of original hair.  (ii) Endodermis with passage cells.  (iii) Presence of pith.  (iv) Radial bundle more than eight.  (v) Excel xylem.  (vi) The occurrence of exodermis.

 The cambium is not formed in the pericycles of the roots of monocots as secondary growth is absent in monocots.  Vascular Strand: It is polygonal and consists of eight or more alternate and radial bundles of xylem and phloem.  The number of xylem and phloem bundles is equal.

 They are in contact with the pericycle in turn.  Phloem bundles are small oval patches.  Phloem is composed of sieve tubes and companion cells.  Phloem fibers are rare.  Phloem parenchyma is absent.

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