Question

Choose the correct statement regarding Ascaris

• A. Hatching of embryo takes place within $10$ hours
• B. Development and moulting takes place in alveoli of lungs
• C. Hatching of embryo takes place in stomach due to lytic enzymes
• D. Adulthood is reached within body of host in $10$ days

Answer 1

The correct option is B Development and moulting takes place in alveoli of lungs

Man acquires infection by directly ingesting Ascaris eggs along with contaminated food or water. The second larva hatches out of the egg in small intestine and penetrates the intestinal wall to enter blood stream. Through the hepatic portal circulation it is carried to liver and then to the heart and is finally transported to lungs via pulmonary artery. Within the alveoli of lungs, the secondlarva moults to become the thirdlarva and grows in size. After about a week, it moults to become fourthlarva that reaches pharynx through trachea. From pharynx it is coughed up and swallowed to reach the intestine, where it moults to become an adult.

So, the correct answer is 'Development and moulting takes place in alveoli of lungs'.