The site of protein synthesis in a cell is the: MCQ with Answer and Explanation

Explanation:
The liver uses the urea cycle (ornithine cycle) to convert highly toxic ammonia, produced from amino acid deamination, into less toxic urea, which is excreted by the kidneys. The kidneys filter urea but do not synthesize it. Pancreas is digestive/endocrine, intestine absorbs nutrients.

Explanation:
The Glomerular Filtration Rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowman's capsule per unit time. In a healthy adult, the normal GFR is approximately 125 ml per minute, which amounts to about 180 liters per day. Almost all of this filtrate is reabsorbed, leaving only 1.5 liters of urine.

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.