Which microorganism is used in baking industry for bread? MCQ with Answer and Explanation

Explanation:
The lac operon in E. coli is a classic example of an inducible operon. It is normally 'off' (repressed) because the lac repressor protein, produced by the 'i' gene, binds to the operator, preventing transcription of the structural genes (z, y, a) needed for lactose metabolism. However, when lactose is present in the environment, it is converted to allolactose, which acts as an inducer. Allolactose binds to the repressor, changing its shape and preventing it from binding to the operator, thus 'inducing' or allowing transcription to occur.

Explanation:
The question describes sieve elements, which are the conducting cells of the phloem, not xylem. Sieve tube elements are living but lack a nucleus at maturity and have perforated end walls called sieve plates. Xylem vessels and tracheids are dead, hollow, and lack perforated end walls (vessels have perforation plates, but they are not called sieve plates). Xylem parenchyma is living.

Explanation:
Lysosomes are membrane-bound vesicles containing hydrolytic enzymes formed by the Golgi apparatus. The Golgi modifies, sorts, and packages proteins from the rough ER into vesicles; some become lysosomes. These organelles function in intracellular digestion and autophagy. Rough ER synthesizes enzymes, but the final packaging into lysosomes occurs at the Golgi. Hence, Golgi is sometimes called the 'traffic police' of the cell.