1. Excretion is the process in which all metabolic wastes are passed out of the body. Excretion in humans occurs in several processes through various organs and internal organs of the body.

2. Diffusion is the most common process of excretion in lower organisms. The human body is an extraordinary machine, where various life-processes (respiration, circulation, digestion, etc.) occur simultaneously. As a result, many of the waste products produced in our bodies are in various forms including carbon dioxide, water, and nitrogenous products such as urea, ammonia, and uric acid.

Bile juice is produced by the liver and stored in the gallbladder, which is a small organ located beneath the liver. When needed, bile is released from the gallbladder into the small intestine to aid in the digestion and absorption of fats and fat-soluble vitamins. So, the correct answer is the liver secretes bile juice, and it is stored in the gallbladder before being released into the small intestine.