List of Scientists and their Contributions | Clas-12 Biology

Dear students, here I have tried to compile all the scientists and their contributions given in the NCERT Class-XII Biology Textbook.

If you have any suggestions or additions, please do put in the comments section.

Happy Studying :)

👨‍🔬 Scientist	🔬 Contribution
Gregor Johann Mendel	a) Father of genetics b) Conducted experiments for the first time to understand the pattern of inheritance and variation.
Reginald C Punnett	Punnett square
Galton	Polygenic inheritance
De Vries, Correns, Von Tschermark	Independently rediscovered Mendel's work.
Walter Sutton & Theodore Boveri	Chromosomal theory of inheritance
Thomas Hunt Morgan	a) Experimental verification of chromosomal theory of inheritance b) Linkage and Recombination
Alfred Sturtevant	Chromosomal or linkage maps
Henking	X-Body (Chromosome)
Friederich Miescher	Nuclein
Maurice Wilkins & Rosalind Franklin	X-ray diffraction data that led to DNA structure discovery
James Watson & Francis Crick	Proposed the structure of double helix model for the DNA Semi-conservative mode of DNA replication
Erwin Chargaff	Chargaff's Rule: A+T = G+C or A+T/G+C=1
Francis Crick	Central Dogma in molecular biology tRNA as adapter molecule
Frederick Griffith	Transforming principle (carried out a series of experiments with streptococcus pneumonia)
Avery, MacLeod, McCarty	Determined the biochemical nature of the transforming principle
Hershey & Chase	The unequivocal proof that DNA is the genetic material
Meselson & Stahl	Experimented to prove DNA replicates semi-conservatively
George Gamow	Genetic codon should be made up of 3 nucleotides
Hargovind Khorana	Developed a chemical method for the synthesis of RNA molecule with defined base combination
Marshall Nirenberg	Put forward a cell free system for protein synthesis that help in deciphering the code
Severo Ochoa	Showed the polynucleotide phosphate also helped in polymerizing RNA with define sequence in a template in depend manners
Jacob & Monod	Lac operon model of gene regulation
Frederick Sanger	a) Developed method for determination of amino acid sequences in protein. b) Automated DNA sequencing
Oparin & Haldane	Proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that formation of life was preceded by chemical evolution.
Louis Pasteur	Disproved spontaneous generation. Experimentally demonstrated that life comes only from pre-existing life.
S.L. Miller	Experiment supporting chemical origin of life
Charles Darwin	Father of Evolution Natural selection Adaptive radiation Reproductive fitness
Alfred Wallace	Natural selection theory; co-contributor with Darwin
Lamark	Use and disuse theory of evolution
Thomas Malthus	Proposed Malthusian theory of population - this theory states that population growth will always tend to out run the food supply. This theory is thought to influence Darwin.
William Harvey	Discovery of blood circulation
Hugo de Vries	Developed mutation theory - saltation
Hardy & Weinberg	Hardy-Weinberg principle - genetic equilibrium in a population.
Norman Borlaug	He improved methods of cultivation and developed a robust strain of wheat. Semi-dwarf wheat.
Alexander Fleming	Discovery of penicillin (antibiotic)
Ernest Chain & Howard Florey	Established the full potential of penicillin as an antibiotics. Mass production and application of penicillin
Cohen & Boyer	First recombinant DNA
Gause	Competitive exclusion principle
MacArthur	Resource partitioning in warblers
Edward Wilson	Coined the term biodiversity
Robert Costanza	Valuation of ecosystem services
Robert May	Estimated global species diversity (~7 million)
Alexander von Humboldt	Species richness increases with area (up to a limit)
David Tilman	More species = stable ecosystems His long-term ecosystem experiments states that plots with more species showed less year-to-year variation in total biomass
Paul Ehrlich	Rivet popper hypothesis (ecosystem stability)