Q4. The protein-synthesising machinery has evolved around RNA. Which NCERT idea about the first genetic material does this support, and why?
The RNA-first hypothesis: the machinery that makes proteins has evolved around RNA, which suggests RNA was at work first, and DNA later took over the storage of information. NCERT’s Summary says translation has evolved around RNA, “indicating that life began around RNA” (reasoned from NCERT pages 87, 88 and 108).
Q5. Assertion: DNA is a better store of genetic information than RNA. Reason: DNA evolved from RNA with chemical modifications that make it more stable. Are both true, and does the reason explain the assertion?
Within NCERT’s RNA-first model, both statements are accepted and improved stability explains DNA’s storage advantage. Scientifically, the chemical comparison is testable, while the exact evolutionary transition remains a hypothesis.
Q6. Where does NCERT say the RNA world will be discussed in detail?
In the chapter on chemical evolution, that is, the evolution chapter (NCERT page 88).