Which of the following workers are related as ecologist, palaeobotanist and embryologist respectively?

Ram Deo Misra (1908-1998) was the father of ecology in India. His researches laid the foundation for understanding of tropical communities and their succession, environmental responses of plant populations, and productivity and nutrient cycling in tropical forests and grassland ecosystems. Birbal Sahni FRS (14 November 1891 – 10 April 1949) was an Indian paleobotanist who studied the fossils of the Indian subcontinent, was also a geologist who took an interest in archaeology. He founded the Birbal Sahni Institute of Palaeobotany in Lucknow, India. His greatest contributions lie in the study of botany of the plants of India as well as paleobotany. Panchanan Maheswari (9 November 1904 – 18 May 1966) was a prominent Indian botanist noted chiefly for his invention of the technique of test-tube fertilization of angiosperms. This invention has allowed the creation of new hybrid plants that could not previously be crossbred naturally.