Correct Answer: 3. A-III, B-II, C-IV, D-I
Solution:A. Chromosome Theory - III. 1903: Proposed by Walter Sutton and Theodor Boveri, the Chromosome Theory of Inheritance in 1903 stated that genes are located on chromosomes, forming the basis for modern genetics.
B. Denver Classification - II. 1959: The Denver system was the first standard classification of human chromosomes into groups (A-G) based on size and centromere position.
C. Paris Nomenclature – IV. 1971: Developed to provide internationally accepted rules for chromosome banding patterns using staining techniques.
D. Human Chromosome Number Confirmation - I. 1956: In 1956, Tjio and Levan conclusively demonstrated that humans have 46 chromosomes, correcting earlier errors (which had listed 48). Hence, the correct chronological pairing is: A-III, B-II, C-IV, D-I.