Tell me which is the best book of biology class 12 cbse board

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

Which statement best describes lactic acid fermentation? a. lactic acid fermentation is the first step of cellular respiration. o b. lactic acid fermentation is the final step of cellular respiration. re to berate c. in the absence of oxygen, cells release atp by breaking down lactose into glucose. e der lade res o d. in the absence of oxygen, cells release atp by breaking down glucose into lactate. ar