A K SHARMA

S K SARKAR

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Cytology of different species of palms and its bearing on the solution of the problems of phylogeny and speciation

Genetica

Further investigations on several genera of Umbelliferae and their interrelationships

A thorough study of the karyotypes has been performed on fourteen different species and varieties of Jasminum in order to fill this lacuna in our knowledge of the cytology of this genus. Improved techniques, involving the use of Aesculine, have been standardized for this purpose. The absence of any detailed study on this aspect has been attributed mainly to the limitations of the methods adopted previously. A general resemblance has been noted in the chromosome morphology between species of Jasininum, indicating that the genus represents a natural assemblage. The different species and varieties have been found to differ from each other in minute details of the karyotype. This fact has been regarded to suggest the important role played by structural alteration of chromosomes in evolution. As each and every species or variety is characterized by a distinct karyotype, the significance of this study in the identification of species has been emphasized. The minor part played by polyploidy and specially, allotetraploidy, before the species concerned lost its capacity for sexual reproduction, has also been pointed out. Variation in chromosome complements has been noted in the same somatic tissue containing normal nuclei and, as sexual propagation is mostly ineffective in this genus, the role of such somatic mutations in speciation of this genus through asexual means has been suggested. © 1958, Japan Mendel Society, International Society of Cytology. All rights reserved.

Fulltext

CYTOLOGIA

Analysis of Chromosome Morphology and Possible Means of Speciation in Jasminum

Caryologia

A new concept of a means of speciation in plants

The action of different prefixing agents including water and a dilute CaCl2 solution on plants with high chromosome number showed that all the solutions tried exhibited marked effect on the physical state of the plasma. Also the plasmatic constitution of the pretreated tissue differed from the appearance of one fixed directly in dye-acid mixture for a few seconds without any pre-treatment. For the clarification of the karyotypes, the best results have been obtained with paradichlorobenzene. It was used as a prefixing agent with a short schedule for temporary smears of difficult materials, particularly those with high chromosome number. The method comprised treatment of the root tips in a saturated aqueous solution of the chemical for 3 hours at 12-16°C., followed by 4-5 seconds heating just to boiling in orcein-hydrochloric acid mixture, then smearing in 1% aceto-orcein solution. © 1955 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.

Biotechnic and Histochemistry

Paradichlorobenzene and other chemicals in chromosome work

Cytology of different species of aroids with a view to trace the basis of their evolution

California Agriculture

Sidebar: Risk assessment defined

Problems of Birth Defects

The Chromosome Number of Man

Journal	Genetica
Publisher	Martinus Nijhoff, The Hague/Kluwer Academic Publishers
ISSN	0016-6707