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Prinnciples of Pure Line Selection

  Pure Line Selection   Pure line selection is one of the oldest and most important methods of plant breeding. It is mainly used for the improvement of self-pollinated crops. In agriculture, many crop plants show natural variation in characters such as plant height, maturity, grain size, seed colour, disease resistance, and yield. A plant breeder studies this variation and selects the best plant from the available population. When the selected superior plant is self-pollinated generation after generation, its progeny becomes highly uniform and stable. This uniform and genetically similar group of plants is called a pure line.   The concept of pure line selection has played a major role in the development of improved crop varieties. It helped breeders convert variable local populations into uniform and high-performing varieties. The method is simple, scientific, and economical, so it has remained a fundamental topic in plant breeding courses. For undergraduate stud...

Dicot Stem Anatomy

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Genetic diversity

  Genetic diversity Genetic diversity refers to the variety and variability of genes within a population or a species. It is a crucial aspect of biological systems and plays a fundamental role in the adaptation and evolution of living organisms. Genetic diversity encompasses the range of different alleles (gene variants) present in a population or species. ·           Importance : 1. Adaptation and Evolution : Genetic diversity is essential for the adaptation and evolution of species over time. It provides the raw material for natural selection to act upon, enabling populations to respond to environmental changes. 2. Resilience : Higher genetic diversity can enhance the resilience of a population to environmental stress, diseases, and other challenges. It reduces the risk of the entire population being wiped out by a single event. 3. Conservation of Biodiversity : Genetic diversity is crucial for the conservation of biodiversity. In c...

āĻ•ৃāώিāĻ•্āώেāϤ্āϰে āĻļৈāĻŦাāϞেāϰ āĻ­ূāĻŽিāĻ•া

  āĻ•ৃāώিāĻ•্āώেāϤ্āϰে āĻļৈāĻŦাāϞেāϰ āĻ­ূāĻŽিāĻ•া      āĻĒ্āϰাāϚীāύāĻ•াāϞ āĻĨেāĻ•ে āĻ•ৃāώিāϜāĻŽিāϰ āωāϰ্āĻŦāϰāϤা āĻŦৃāĻĻ্āϧিāϰ āϜāύ্āϝ āϏাāĻŽুāĻĻ্āϰিāĻ• āĻļৈāĻŦাāϞ āĻŦ্āϝāĻŦāĻšৃāϤ āĻšāϝ়ে āφāϏāĻ›ে । āϜৈāĻŦ āϏাāϰ āĻšিāϏেāĻŦে āĻŦাāĻĻাāĻŽি āĻļৈāĻŦাāϞ āĻ“ āϞোāĻšিāϤ āĻļৈāĻŦাāϞেāϰ āĻĒ্āϰāϚāϞāύ āφāĻ—ে āĻĨেāĻ•ে āĻ›িāϞ । āϏ্āĻĨāϞāϜ āĻļৈāĻŦাāϞ āĻŽাāĻ েāϰ āĻĒাāύি āϏāĻž্āϚাāϞāύ āĻ•্āώāĻŽāϤা āĻŦৃāĻĻ্āϧি āĻ•āϰে । āĻ­ূāĻŽিāĻ•্āώāϝ় āϰোāϧ āĻ•āϰে । āύāϤুāύ āĻŽাāϟি āĻ—āĻ āύ āĻ•āϰে āĻ“ āϏংāϰāĻ•্āώāĻŖ āĻ•āϰে āĻŽাāϟিāĻ•ে āĻ•ৃāώিāĻ•াāϜেāϰ āωāĻĒāϝোāĻ—ী āĻ•āϰে āϤোāϞে । ⧍ā§Ļ āϟিāϰ āĻ…āϧিāĻ• āύীāϞাāĻ­ āϏāĻŦুāϜ āĻļৈāĻŦাāϞ āĻŦাāϤাāϏেāϰ āύাāχāϟ্āϰোāϜেāύ āϏংāĻŦāύ্āϧāύ āĻ•āϰে āϜāĻŽিāϰ āωāϰ্āĻŦāϰāϤা āĻŦৃāĻĻ্āϧি āĻ•āϰে । āĻāĻĻেāϰ āĻŽāϧ্āϝে Nostoc , Anabaena , Scytonema , Oscillatoria āωāϞ্āϞেāĻ–āϝোāĻ—্āϝ । āϏাāĻŽুāĻĻ্āϰিāĻ• āĻļৈāĻŦাāϞেāϰ āĻĻেāĻšে āĻĢāϏāĻĢāϰাāϏ , āĻĒāϟাāĻļিāϝ়াāĻŽ āĻāĻŦং āĻ…āύ্āϝাāύ্āϝ āϰাāϏাāϝ়āύিāĻ• āĻĒāĻĻাāϰ্āĻĨেāϰ āϏাāĻŽাāύ্āϝ āĻĒāϰিāĻŽাāĻŖে āωāĻĒāϏ্āĻĨিāϤিāϰ āĻ•াāϰāĻŖে āϏāĻŽুāĻĻ্āϰ āωāĻĒāĻ•ূāϞāĻŦāϰ্āϤী āĻŦিāĻ­িāύ্āύ āĻĻেāĻļে āĻ•ৃāώি āϜāĻŽিāϰ āωāϰ্āĻŦāϰāϤা āĻŦৃāĻĻ্āϧিāĻ•āϞ্āĻĒে āϏাāĻŽুāĻĻ্āϰিāĻ• āĻļৈāĻŦাāϞ āĻāĻŦং āĻ•āĻ–āύāĻ“ āĻ•āĻ–āύāĻ“ āϏ্āĻŦাāĻĻু āĻĒাāύিāϰ āĻļৈāĻŦাāϞ āϏাāϰ āĻŦা āĻĢাāϰ্āϟিāϞাāχāϜাāϰ āĻšিāϏেāĻŦে āĻŦ্āϝāĻŦāĻšৃāϤ āĻšāϝ় । āϏাāϰ āĻšিāϏেāĻŦে āĻŦ্āϝāĻŦāĻšাāϰ্āϝ āĻļৈāĻŦাāϞāϏāĻŽূāĻšেāϰ āϤাāϞিāĻ•া āύিāĻŽ্āύāϰূāĻĒ : ā§§. āϝেāϏāĻŦ āĻ•ৃāώি āϜāĻŽিāϤে āĻ•্āϝাāϞāϏিāϝ়াāĻŽ āϘাāϟāϤি āφāĻ›ে āϏেāĻ–াāύে Lithophyllum , Lithothamnion , Chara āĻĒ্āϰāĻ­ৃāϤি āĻ—āĻŖেāϰ āĻļৈāĻŦাāϞেāϰ āĻĨ্āϝাāϞাāϏāĻ•ে āϏাāϰ āĻšিāϏেāĻŦে āĻŦ্āϝāĻŦāĻšাāϰ āĻ•āϰāϞে āϜāĻŽিāϰ Ca āϘাāϟāϤি āĻĒূāϰāĻŖ āĻšāϝ় । ⧍. āφāϝ়াāϰāϞ্āϝাāύ্āĻĄেāϰ āĻ•ৃāώāĻ•েāϰা ...

āĻŦিāώাāĻ•্āϤ āĻļৈāĻŦাāϞ āĻŦāϞāϤে āĻ•ী āĻŦোāĻ?

  āĻŦিāώাāĻ•্āϤ āĻļৈāĻŦাāϞ āĻŦāϞāϤে āĻ•ী āĻŦোāĻ ?    Microcystis , Anabaena , Nodularia , Glocotrichia   āĻāĻŦং Aphanizomenon āύাāĻŽāĻ• āύীāϞাāĻ­ - āϏāĻŦুāϜ āĻļৈāĻŦাāϞāĻ—ুāϞো āĻāĻŽāύ āĻ•িāĻ›ু Endotoxin āύিঃāϏāϰāĻŖ āĻ•āϰে āϝা āĻ—āϰু,āĻ›াāĻ—āϞ, āĻŽāĻšিāώ , āϘোāĻĄ়া, āĻ­েāĻĄ়া   āĻĒ্āϰāĻ­ৃāϤি āĻĒāĻļুāϰ āĻ–াāĻĻ্āϝāύাāϞিāϤে āĻĒ্āϰāĻŦেāĻļ āĻ•āϰāϞে āϐ āϏāĻŦ āĻĒ্āϰাāĻŖী āĻŽৃāϤ্āϝুāĻŽুāĻ–ে āĻĒāϤিāϤ āĻšāϝ় । āĻĒāĻļুāĻ—ুāϞোāϰ āĻŽৃāϤ্āϝুāϰ āϏাāĻĨে āϏাāĻĨে āϐ āĻŦিāώāĻ•্āϰিāϝ়া āύāώ্āϟ āĻšāϝ় ।  āĻļৈāĻŦাāϞ āĻŽিāĻļ্āϰিāϤ  āϜāϞ āĻĒাāύ āĻ•āϰে ⧍ā§Ē āϘāĻŖ্āϟাāϰ āĻŽāϧ্āϝে āĻ—ৃāĻšāĻĒাāϞিāϤ āĻĒ্āϰাāĻŖীāϰ āĻŽৃāϤ্āϝুāϰ  āϘāϟāύা āϘāϟাāϰ āĻ•āĻĨাāĻ“ āϜাāύা āĻ—েāĻ›ে । āĻŽৃāϤ্āϝু āĻ›াāĻĄ়াāĻ“ āĻĒāĻļু āĻĻেāĻšেāϰ āĻ­িāϤāϰে āĻ•িāĻ›ু  āĻ•িāĻ›ু āĻļৈāĻŦাāϞ āĻāĻŽāύ āĻŦিāϰূāĻĒ āĻĒ্āϰāϤিāĻ•্āϰিāϝ়া āϏৃāώ্āϟি āĻ•āϰে āϝাāϰ āĻĢāϞে āĻĒāĻļুāϰ āĻļাāϰীāϰিāĻ• āĻ“āϜāύ āĻ•āĻŽে āϝাāϝ় , āϝāĻ•ৃā§Ž āφāĻ•্āϰাāύ্āϤ āĻšāϝ়ে āĻ…āύ্āϝ āĻ•োāύো āϰোāĻ— āϏৃāώ্āϟি āĻšāϝ় , āĻ…āĻĨāĻŦা āĻĒāĻļুāϟি āĻ—āϰ্āĻ­āĻŦāϰ্āϤী āĻĨাāĻ•āϞে āĻ—āϰ্āĻ­āĻĒাāϤ āϘāϟে । āĻ•āĻ–āύāĻ“ āĻ•āĻ–āύāĻ“ āĻ•িāĻ›ু āĻ•িāĻ›ু āĻļৈāĻŦাāϞ āĻŽাāύুāώেāϰ āĻŽৃāϤ্āϝুāϰāĻ“ āĻ•াāϰāĻŖ āĻšāϝ়ে āĻĻাঁāĻĄ়াāϤে āĻĒাāϰে । Gonyaulax catanella āύাāĻŽāĻ• āĻāĻ•āϟি āĻļৈāĻŦাāϞ āĻŽাāĻ›েāϰ āĻ–াāĻĻ্āϝ । āϐ āĻļৈāĻŦাāϞ āĻĨেāĻ•ে āύিঃāϏৃāϤ Endotoxin āĻŽাāĻ›েāϰ āĻĻেāĻšে āϏāĻž্āϚিāϤ āĻšāϤে āĻĨাāĻ•ে । āϝেāϏāĻŦ āĻŽাāĻ› Gonyaulax   catanella āĻļৈāĻŦাāϞ āĻ–াāϝ় āϏে āĻŽাāĻ› āĻ•োāύো āĻŽাāύুāώেāϰ āĻ–াāĻĻ্āϝ āĻšāϞে āϏেāχ āϟāĻ•্āϏিāύ āĻŽাāύুāώেāϰ āĻŽৃāϤ্āϝু āϘāϟাāϝ় । āĻāĻ›াāĻĄ়াāĻ“ Microcystis āĻāĻŦং Anabaena āĻŽা...

āϞোāĻšিāϤ āĻļৈāĻŦাāϞ āύীāϞাāĻ­ āϏāĻŦুāϜ āĻļৈāĻŦাāϞ

  āϞোāĻšিāϤ   āĻļৈāĻŦাāϞ āύীāϞাāĻ­ āϏāĻŦুāϜ āĻļৈāĻŦাāϞ ā§§ . āĻāϰা āĻĒ্āϰāĻ•ৃāϤ āĻ•োāώী   ā§§ . āĻāϰা āφāĻĻি āĻ•োāώী   ⧍ . āĻ•োāώে āĻĒāĻĻাāĻŦৃāϤ āĻ…āĻ™্āĻ—াāĻŖু āĻĨাāĻ•ে ৷ ⧍ . āĻ•োāώে āĻ•োāύো āĻĒāĻĻাāĻŦৃāϤ āĻ…āĻ™্āĻ—াāĻŖু āĻĨাāĻ•ে āύা ।   ā§Š . āĻ•োāώ āĻĒ্āϰাāϚীāϰে āĻŽিāωāϰাāĻŽিāĻ• āĻāϏিāĻĄ āĻĨাāĻ•ে āύা ।   ā§Š . āĻāĻĻেāϰ āĻ•োāώ āĻĒ্āϰাāϚীāϰে āĻŽিāωāϰাāĻŽিāĻ• āĻāϏিāĻĄ āĻĨাāĻ•ে     ā§Ē .   āϝৌāύ āϜāύāύ āĻĻেāĻ–া āϝাāϝ় । ā§Ē . āϝৌāύ āϜāύāύ āĻĻেāĻ–া āϝাāϝ় āύা ।   ā§Ģ . āĻ…āϧিāĻ•াংāĻļ āĻļৈāĻŦাāϞে āĻšেāϟেāϰোāϏিāϏ্āϟ āϤৈāϰি āĻšāϝ় āύা   ā§Ģ . āĻ…āϧিāĻ•াংāĻļ āĻļৈāĻŦাāϞে āĻšেāϟেāϰোāϏিāϏ্āϟ   āϤৈāϰি āĻšāϝ় ā§Ŧ . āĻĒেāĻ•āϟিāύ āύিঃāϏৃāϤ āĻ•āϰে āύা । ā§Ŧ . āĻĒেāĻ•āϟিāύ āύিঃāϏৃāϤ āĻ•āϰে ।   ā§­ . āωāĻĻাāĻšāϰāĻŖ - Polysiphonia , Gelidium     ā§­ . āωāĻĻাāĻšāϰāĻŖ - Nostoc , Anabaena

āĻŽāϏ āĻāĻŦং āĻĢাāϰ্āĻŖ (āϏংāĻ•্āώিāĻĒ্āϤ āĻĒ্āϰāĻļ্āύোāϤ্āϤāϰ) Part 2

  ā§§ā§Ŧ. āϰাāχāϜোāĻĢোāϰ āĻ•াāĻ•ে āĻŦāϞে ? Rhizophore āĻĻুāϟি āĻ—্āϰিāĻ• āĻļāĻŦ্āĻĻ āύিāϝ়ে āĻ—āĻ িāϤ । Rhiza = āĻŽূāϞ āĻāĻŦং Phora = āĻŦāĻšāύāĻ•াāϰী । āϏুāϤāϰাং, āĻĒাāϤাāĻŦিāĻšীāύ āϏিāϞিāύ্āĻĄাāϰ āφāĻ•ৃāϤিāϰ āĻŽূāϞ āĻŦāĻšāύāĻ•াāϰী āĻ•াāĻ“āĻ•ে āϰাāχāϜোāĻĢোāϰ āĻŦāϞা āĻšāϝ় । āϰাāχāϜোāĻĢোāϰেāϰ āύিāϚেāϰ āĻĻিāĻ•ে āĻŽূāϞ āϏৃāώ্āϟি āĻšāϝ় । āĻāϟি Selaginella āϤে āĻĻেāĻ–া āϝাāϝ় । ā§§ā§­. āϏ্āĻĒোāϰোāĻĢাāχāϟ āĻ“ āĻ—্āϝাāĻŽিāϟোāĻĢাāχāϟ āĻ•াāĻ•ে āĻŦāϞে ? āωāĻĻ্āĻ­িāĻĻেāϰ āϜীāĻŦāύāϚāĻ•্āϰে āĻĻুāϟি āĻĻāĻļা āφāĻ›ে । āĻāĻ•āϟি āĻĻāĻļা āĻšāϞো āϏ্āĻĒোāϰোāĻĢাāχāϟিāĻ• āĻ…āύ্āϝāϟি āĻ—্āϝাāĻŽিāϟোāĻĢাāχāϟিāĻ• । āϏ্āĻĒোāϰাāĻĢাāχāϟিāĻ• āĻĻāĻļাāϟি āĻĄিāĻĒ্āϞāϝ়েāĻĄ āĻ…āϰ্āĻĨাā§Ž 2n āϏংāĻ–্āϝāĻ• āĻ•্āϰোāĻŽোāϜোāĻŽ āϏāĻŽৃāĻĻ্āϧ āĻāĻŦং āĻ—্āϝাāĻŽিāϟোāĻĢাāχāϟিāĻ• āĻĻāĻļাāϟি āĻš্āϝাāĻĒ্āϞāϝ়েāĻĄ āĻ…āϰ্āĻĨাā§Ž n ( āĻ…āϰ্āϧেāĻ• / Half ) āϏংāĻ–্āϝāĻ• āĻ•্āϰোāĻŽোāϜোāĻŽ āϏāĻŽৃāĻĻ্āϧ । Sporophyte āĻļāĻŦ্āĻĻāϟি āĻŦিāĻļ্āϞেāώāĻŖ āĻ•āϰāϞে āĻĒাāĻ“āϝ়া āϝাāϝ় Sporous > Spore = āϰেāĻŖু , Phyton > Phyte=āωāĻĻ্āĻ­িāĻĻ / āωāĻĻ্āĻ­িāĻĻāĻĻেāĻš ।  āϏুāϤāϰাং , āωāĻĻ্āĻ­িāĻĻেāϰ āϏ্āĻĒোāϰ āĻŦা āϰেāĻŖুāĻŦাāĻšী āĻĻāĻļাāĻ•েāχ āϏ্āĻĒোāϰোāĻĢাāχāϟিāĻ• āĻĻāĻļা āĻāĻŦং āϏ্āĻĒোāϰ āĻŦা āϰেāĻŖুāĻŦাāĻšী āĻ…āĻ™্āĻ— / āĻĻেāĻšāĻ•ে āϏ্āĻĒোāϰোāĻĢাāχāϟ āĻŦāϞা āĻšāϝ় । āφāϰ āφāĻŽāϰা āϜাāύি , āϏ্āĻĒোāϰāĻŦāĻšāύāĻ•াāϰী āωāĻĻ্āĻ­িāĻĻāĻĻেāĻš āĻĻুāϟি āĻš্āϝাāĻĒ্āϞāϝ়েāĻĄ āĻ—্āϝাāĻŽিāϟেāϰ āĻŽিāϞāύেāϰ ( n + n ) āĻĢāϞে āĻ‰ā§ŽāĻĒāύ্āύ āĻšāϝ় । āĻāϜāύ্āϝ āϏ্āĻĒোāϰāĻŦাāĻšী āωāĻĻ্āĻ­িāĻĻ āĻĄিāĻĒ্āϞāϝ়েāĻĄ 2n . āϏ্āĻĒোāϰোāĻĢাāχāϟ āĻĒāϰিāĻŖāϤ āĻšāϞে āϏ্āĻĒোāϰাāĻž্āϜিāϝ়াāĻŽেāϰ āĻ­েāϤāϰে āĻŽাāϝ়োāϏিāϏ āĻ•োāώ āĻŦিāĻ­াāϜāύেāϰ āĻŽাāϧ্āϝāĻŽে āĻš্āϝাāĻĒ্āϞāϝ়েāĻĄ ( n ) āϏ্āĻĒোāϰ āĻ‰ā§ŽāĻĒāύ্āύ āĻ•...

Bryophyte short question

  Bryophyte short question Q. 1. What is gemma cup ? The most common method of the vegetative reproduction in some bryophytes take place by means of especially designed vegetative bodies, the gemma, which originated from the cup - like structure, the gemma cup, found on the dorsal surface of the thallus or at the rhizoidal portion . E.g. Marchantia sp . Q. 2 .   What are elaters ? In some bryophytes like Marchentia , within capsule are found some exceptionally long , slender sterile cells known as elaters . They have double spiral thickening, the mature elaters lack protoplasm and function in spore dispersal . Q. 3. What is air channel ? In Riccia's photosynthetic zone there present green or chlorenchymatous cells which are arranged in vertical rows or column. Between the columns of green cells very   narrow, deep, vertical slits are formed. These slits are called air channels. Q. 4 .   What is nurse cells ? Pagan (1932) reported the sterility of som...