UPSC 2012: With reference to the scientific progress of ancient India, which of the statements given below are correct? 1. Different kinds of specialized surgical instruments were in common use by 1st century AD. 2. Transplant of internal organs in the human body had begun by the beginning of 3rd century AD. 3. The concept of sine of an angle was known in 5th century AD. 4. The concept of cyclic quadrilaterals was known in 7th century AD.

Sushruta Samhita (c.​1st cent. AD or earlier) lists dozens of metal surgical instruments, so statement 1 is correct. Actual transplantation of internal organs is not recorded in ancient Indian texts, making statement 2 incorrect. Aryabhata introduced the trigonometric ‘jya’ (sine) in the 5th century AD, and Brahmagupta described properties of cyclic quadrilaterals in the Brahmasphutasiddhanta in the 7th century AD, validating statements 3 and 4. Therefore, only 1, 3 and 4 are correct. ([edukemy.com](https://edukemy.com/blog/upsc-prelims-2024-subject-wise-bullet-points-indian-history/?utm_source=openai))