The disease caused by the deficiency of iodine is: MCQ with Answer and Explanation

Explanation:
The cochlea, a spiral-shaped organ in the inner ear, contains the organ of Corti with hair cells that transduce mechanical vibrations into electrical impulses. The eardrum and ossicles conduct sound to the cochlea. The auditory nerve transmits impulses to the brain. Thus, transduction occurs in the cochlea.

Explanation:
Lactobacillus is a lactic acid bacterium that ferments lactose in milk, producing lactic acid that coagulates proteins to form curd. Saccharomyces cerevisiae (baker's yeast) undergoes anaerobic respiration, producing CO2 gas that causes bread dough to rise. Aspergillus niger, a fungus, is widely used in industrial fermentation for the large-scale production of citric acid. All statements are correct.

Explanation:
The sinoatrial (SA) node, located in the right atrium, generates electrical impulses spontaneously and initiates each heartbeat, setting the rhythm. It is called the natural pacemaker. The atrioventricular (AV) node delays the impulse before it travels to the ventricles. The bundle of His and Purkinje fibers conduct the impulse through the ventricles.