Which organelle is the site of photosynthesis? MCQ with Answer and Explanation

Explanation:
Oxytocin stimulates uterine smooth muscle contractions during childbirth and milk ejection during lactation. Thyroxine regulates metabolism; calcitonin and parathyroid hormone control blood calcium. Insulin lowers blood glucose. Adrenaline increases heart rate, not decreases. This question tests the core functions of major hormones.

Explanation:
The Lac operon in E. coli is a classic example of an inducible operon. It is normally 'off' (repressed) because a repressor protein binds to the operator, preventing transcription. However, when the inducer (allolactose, derived from lactose) is present, it binds to the repressor, inactivating it and allowing RNA polymerase to transcribe the genes needed for lactose metabolism.

Explanation:
Certain high-risk strains of HPV are a major cause of cervical cancer. Vaccines are available. TB is bacterial, malaria protozoan, cholera bacterial.