11 public questions tagged with this topic.
Alfred Wallace independently arrived at the theory of natural selection while working in the Malay Archipelago. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Evolution, Topic: Theories, Hardy-Weinberg principle and evidences.
The observation that a small fraction of alpha-particles were deflected by large angles (e.g., more than 90°) indicated a small, dense, positively charged nucleus at the atom’s nter.
Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Relevant Physics topic covering fundamental principles,
J.J. Thomson’s experiments with cathode rays led to the discovery of electrons as fundamental negatively charged particles in matter. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.
Ref: NCERT Physics Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII, continuing as per NCERT advisory for 2026-27),Topic: Fundamental laws, definitions and applications as per latest NCERT. The section explains governing laws, formulas like μ₀ = 4π.
Mendel chose pea plants because they have a short life cycle and well-defined contrasting traits. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.
Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -
John Dalton, in 1808, proposed the atomic theory, considering the atom as the smallest indivisible unit of matter, explaining laws like conservation of mass.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Relevant Chemistry topic covering principles and examples as per NCERT.
Jan Ingenhousz showed that green plants release oxygen in the presence of sunlight. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.
Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -
Aristotle, fourth century BC, authored Historia Animalium and De Generatione Animalium, observing chick embryo development, cephalopod eggs, and bee metamorphosis. He compared morphologies across species, proposed epigenesis versus preformation, and recognized similarities in vertebrate organization long before microscopy. His systematic dissection and staging of embryos established foundation for comparative developmental anatomy. Later investigators like von Baer, Müller, and Wolpert built upon evolutionary embryology, but Aristotle remains first known scholar to integrate descriptive embryo
Ref: Aristotle, De Generatione Animalium; Gilbert, 12th ed., Chapter 1: History of embryology.
Dmitri Ivanowsky observed that the agent causing tobacco mosaic disease passed through bacteria-proof filters. This indicated that the infectious agent was smaller than bacteria.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Bacteria - Structure and Economic Importance
Term taxonomy for theoretical study of plant classification introduced by Augustin Pyramus de Candolle in influential treatise Théorie élémentaire de la botanique 1813, deliberately constructed from Greek roots to denote lawful arrangement. Carolus Linnaeus provided binomial nomenclature and sexual system but did not coin taxonomy term itself, Charles Darwin explained natural selection not terminology, Julian Huxley later proposed new systematics biosystematics. De Candolle's contribution separated taxonomy as scientific discipline dealing with identification, nomenclature and classification b
Ref: Meyers, History Botany; NCERT, De Candolle Theorie elementaire 1813 taxonomy term
