In: Biology
9. How does the answer to question 8 differ from that of a fetal pig?
"Question 8. Describe briefly how Hydra digests food and removes waste from itself."
8)Digestion in Hydra :- Extracellular digestion .
Hydra have tentacles ,on these tentacles stinging cells are present .As ,prey comes near these stinging cells, these cells inject poison in the prey .So,prey become paralyzed.
With the help of tentacles hydra trap its food into gastrovascular cavity.Inside the cavity enzymes breakdown the food into smaller pieces and the food is semidigested ,now semidigested food is fully digested inside the food vacuole ( means via intracellular digestion) .Nutrients are absorbed and energy is consumed by various activities.
Excretion in Hydra :- Ammonotelic organism ( excrete ammonia) .Hydra is have incomplete digestive system means a single opening ( act as mouth as well as anus).So,ammonia is formed inside the cell and excreted via mouth .
Digestion in fetal pig :- Extracellular digestion .Have complete digestive system ( two openings :- mouth ,anus)
First food enters inside mouth -- oesophagus -- stomach --small intestine -- large intestine .
Excretion is via kidneys .Pig is a ureotelic organism.