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Showing posts with the label Class 12 Biology

Batrachospermum :Origin ,strucutre ,Thallus organisation and reproduction

                                              Batrachospermum Occurrence:-   (1) Batrachospermum is fresh water alga.    (2) It is found in clear, cool, and running streams.   (3) Deepwater plants are dark violet or reddish in color. But the shallow-water species are olive green.   (4) The intensity of light changes the color of pigments.   (5) The thallus is attached to the substratum. Vegetative structure  (1) The thallus of an adult plant is soft, thick, filamentous.  (2) It is freely branched and gelatinous.   (3) The central axis is made up of a single row of large cells. Whorls of branches of limited growth        are developed on this axis.  (4) These branches are filamentous and dichotomously arranged.  (5) The main axis is corticated. It consists of a row of elongated cylindrical cells.   (6) It is differentiated into nodes and internodes.   (7) There are two types of branches that arise from the nodes:       Branches of limited growth        Branches of unlimited growth Batra

Human Reproductin Class 12th Notes-Male Reproductive Part

                               Human Reproduction The Male Reproductive Part:-                                                 It includes a pair of the testis, glands, and external genitalia. 1. The testis is present outside the abdominal cavity within a pouch-like structure called Scrotum. 2. The scrotum helps in maintaining its temperature - 2C lower than normal body temperature, because it is necessary for spermatogenesis. 3. Each testis has 250 compartments called testicular lobules. 4. Each testicular lobules contain 2-3 seminiferous tubules 5. Seminiferous tubules contain Male germ cells(Spermatogonia) and steroli cells, Male germ cells meiotically divide and form sperms. 6. Leydig's cells provide nourishment to the sperms and secrets of the Androgens hormone. 7. Male sex accessory includes Rete testis, vasa efferentia, epididymis, and vasa deferentia. Sperm release Pathway    The male accessory glands include paired  seminal vesicles , prostat

Plant Physiology -Transpiration and Movment of Mineral and food

                                            Transpiration of Water and Food Means of Transport 3 suggests that of transport in plants: Diffusion Facilitated Diffusion Transport Transpiration Diffusion:- movement of molecules from high concentration to low concentration while not a semi-permeable membrane. · Slow method · No expenditure of energy · Diffusion depends upon: Concentration gradient, porousness of the membrane, Temperature, Pressure and Size of the substance. F aciilated Transport :- · In facillated diffusion, the membrane proteins ar concerned. they supply a web site for hydrophilic   molecules to have the membrane and no energy is needed.   · Proteins concerned within the method type channels which can invariably be opened or controlled. Facillated diffusion is incredibly specific .  · Porins: - Proteins that forms vast pores within the outer membranes of plastids, mitochondria, e

Stratergies of Enhancement in food Production

                  Stratergies for improvement in   food production Animal Breeding :- Mating and croos of animal to enhance its varity or phylogeny quality or yield . Animal Husbandary :- The agricultural apply of breeding   and raising eutherian mammal ,e.g. cow,pig,buffaloes,horses etc. Breeding :- Bee keeping production of honey,Dairy farm is that the management   of animal for milk and its production for human consumption. Fisheries :- An trade dedicated to rearing ,catching,processing of commerce of fish shellfish or alternative aquatic animals. Green Revolution :- Dramatic increase in food production in Nineteen Sixties as a results of caultivation of high yielding illness resistance varities of wheat rise and maize etc. developed through breeding techniques is reffered to as revolution . Mutual Breeding :- Obtaining of crop plants with fascinating characters by artificial or evoked mutation and mistreatment them a cloth in br