Q4. Why does NCERT call fermentation hazardous?
Because either acid or alcohol is produced (NCERT page 157).
Q5. Assertion: fermentation releases little of the energy in glucose. Reason: in fermentation the oxidation of glucose is incomplete. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion: less than seven per cent of the energy in glucose is released (NCERT page 157).
Q6. In which organisms does fermentation take place, according to NCERT?
Under anaerobic conditions in many prokaryotes and unicellular eukaryotes, such as yeast (NCERT page 157), and in germinating seeds (NCERT Summary, page 164); muscle cells also make lactic acid when oxygen is inadequate (page 157).