The scientist who discovered the bacterium that causes leprosy was: MCQ with Answer and Explanation

Explanation:
Bombyx mori is the domesticated silkworm, whose caterpillar spins a silk cocoon. The silk thread is obtained by boiling cocoons. Apis mellifera is the honeybee, Labeo rohita is a fish (rohu), Drosophila is fruit fly used in genetics. Sericulture involves mulberry cultivation, silkworm rearing, and reeling of silk. India is the second largest silk producer.

Explanation:
Relaxin is a peptide hormone produced by the corpus luteum and the placenta during pregnancy. Its primary roles are to relax the smooth muscles of the uterus (inhibiting contractions to maintain pregnancy) and to soften and increase the flexibility of the connective tissues in the pelvis, specifically the pelvic ligaments and the pubic symphysis. This relaxation and widening of the pelvic joints facilitate the passage of the baby through the birth canal during delivery.

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.