Final answer:
The life cycle of Ascaris lumbricoides starts with contaminated food or water. The eggs hatch in the intestine and the larvae travel to the lungs and then to the pharynx before returning to the intestines to mature. Adult worms lay eggs that leave the host via feces.
Step-by-step explanation:
The life cycle of Ascaris lumbricoides starts when eggs are transmitted through contaminated food or water and hatch in the intestine. The juvenile larvae then travel to the lungs and eventually to the pharynx where they are swallowed and returned to the intestines to mature. This cycle repeats as the adult worms lay eggs that leave the host via feces.