Question

Arrange these discoveries in chronological order from oldest to latest.

i. Isolation of nucleic acid
ii. Heredity factors
iii. Model of DNA molecule
iv. Human Genome Project

• A. i$\to$ii$\to$iii$\to$iv
• B. ii$\to$i$\to$iv$\to$iii
• C. ii$\to$i$\to$iii$\to$iv
• D. iv$\to$iii$\to$i$\to$ii

Answer 1

The correct option is C ii$\to$i$\to$iii$\to$iv

• Gregor Johann Mendel based on his experiments on pea plants concluded that certain heredity factors were responsible for transmission of traits from parents to offsprings. He published his results in 1866 but was later recognised in 20th century.
• Friedrich Miescher in 1869, isolated a compound called nucleic acid.
• Watson and Crick proposed 'double helix model of DNA" in 1953. DNA molecule as per this model had two parallel threads of nucleotides which were helically twisted and bonded together by hydrogen bonds.
• Later in 1990, Human Genome Project was undertaken to decode complete DNA sequence of the human genome.