• Varsha Singh

      Articles written in Resonance – Journal of Science Education

    • Sydney Brenner (1927–2019)

      Varsha Singh

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    • Sydney Brenner: The Tamer of an Elegant Worm

      Kaling Danggen Varsha Singh

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      Contributions of Sydney Brenner, one of the recipients of theNobel Prize in Physiology and Medicine in 2002, to the areaof molecular biology and genetics remain unparalleled. Heis undoubtedly the most famous South African biologist withcontribution to the central dogma (DNA to RNA to protein)of molecular biology, and for proving that non-overlappingtriplet codons specify amino acids in a peptide. He pioneeredthe use of molecular biology to understand animal development.Although inspired by T H Morgan and H J Muller,Brenner found eutelic organisms, with a fixed number of cellsin adult individuals, to be better models to understand howan entire organismcomes to be from a zygote. His selection ofCaenorhabditis elegans was so well thought out that it allowedhim not only to perform lineage analysis for each of the 959cells but also let White and Brenner draw the entire wiringdiagram for the nervous system of C. elegans, a feat not accomplishedfor any other animal so far. We intend this articleto summarize some of the key findings of Sydney Brenner’swork on C. elegans spanning two decades.

    • Lynn Margulis: The Champion of Symbiogenesis

      Varsha Singh

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    • The Origin of Eukaryotic Cells

      Varsha Singh

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      The origin of life on Earth is a question of great interest. The origin of eukaryotic cells is yet another question that has boggled evolutionary biologists, naturalists, cell biologists, and molecular biologists alike for quite a while. Although the question is far from settled, evidence suggests that some of the organelles in the present-day eukaryotic cells have arisen from symbiosis events. This article examines morphological and some molecular evidence for the endosymbiotic origin of mitochondria and plastids in eukaryotes. Many of these arguments are based on a classic paper by naturalist and microbiologist Lynn Margulis and follow up work from other scientists. She described eukaryotes as multigenome systems, where all biochemical reactions are encoded in the DNA of either the nucleus or the subcellular organelles of symbiotic origin.

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