Study the schematic representation of the genes involved in the lac operon given below and answer the questions that follow:

The protein produced by the i gene has become abnormal due to unknown reasons. Explain its impact on lactose metabolism stating the reason.

Study the schematic representation of the genes involved in the lac operon given below and answer the questions that follow : {:(p,i,p,o,z,y,a):} (a) Identify and name the regulatory gene in this operon. Explain its role in 'switching off' the operon. (b) Why is the lac operon's regulation referred to as negative regulation ? (c ) Name the inducer molecule and the products of the genes 'z' and 'y' of the operon. Write the functions of these gene products.

Study the figure given below and answer the questions: (i) How does the repressor molecule get inactivated? (ii) When does the transcription of lac mRNA stop? (iii) Name the enzyme transcribed by the gene Z'.

Study the figure given below and answer the questions : (a) What does the figure express ? (b) When does the transcription of lac mRNA stop ? ( c) Name the enzyme transcribed by the gene 'Z'.