Biology
A fertilised egg of the Ascaris lumbricoides - fertilised eggs are round and have a thick shell.
Size
Ascaris worms are very long. Adult females grow up to half a metre long, and males are15–31cm in length. They vary in diameter from 2–6mm.
Life cycle
- ingested Ascaris eggs hatch out into larval worms in the intestine
- worms pass through the intestine wall into the bloodstream
- worms travel via the liver and heart into the lungs
- after 3 weeks they are coughed up, swallowed and return to the gut
- male and female worms mate and female worm produces eggs
- eggs pass out in the stool and become infectious after 2 weeks in the soil