Recapitulation is a bold and influential idea that is particularly associated with Ernst Haeckel though many other biologists also supported it in the nineteenth and early twentieth centuries. According to the theory of recapitulation, the stages of an organism’s development correspond to the species’ phylogenetic history- in a phrase, “ontogeny recapitulates phylogeny.” Each stage in development corresponds to (that is, [...]
Read this article in Hindi to learn about the concept of cultural and ecological development in humans. व्यक्ति के चारों ओर जो कुछ भी है, वही उसकी वातावरणीय परिस्थितियों की ओर संकेत करता है । बोरिंग लैंगफील्ड तथा वेल्ड के विचारानुसार, “जीन्स के अतिरिक्त व्यक्ति को प्रभावित करने वाली वस्तु परिस्थिति है....| एक व्यक्ति के वातावरण से आशय उन समस्त [...]
Development of chemotherapy may be viewed in three phases:- 1. Pre Ehrlich Period 2. Period of Paul Ehrlich 3. Period highlighted by discovery of sulfonamides and antibiotics. Phase # 1. Pre Ehrlich Period: In this period some compounds were used empirically to treat different diseases. Sometimes adverse effects were also monitored due to empirical use of the compounds. Cinchonabark was [...]