PATHOLOGY

Detailed explanation-1: -Infectivity of the eggs was studied by oral egg inoculation in mice and showed that the L3 are the infective stage for mice. Molting to the L3 stage occurs gradually over a period of 2-6 wk, and it is recommended to have an additional maturation period so the infectivity of an egg batch may reach maximum level.

Detailed explanation-2: -Ascaris is monogenetic since it has only one host, the man directly in whom infection occurs. Spiral, determinate, and holoblastic are cleavage. Few days after cleavage, the first larvalis developed and is called the rhabditiform larva or first larva, which is not an infectious stage.