1.The functions of
pseudopodia in amoeba is locomotion and feeding. The pseudopodia gathers itself around the food particle
forming a sort of food cup and thus the food is taken inside the food vacuole. Similarly the tentacles are present near the hypostome of hydra. It also encircles its prey. Hence both the organs are homologous.
2.Hypnotoxin is the mixture of phenols and hormones. It paralyzes its prey as soon the nematocyst is discharged over it.
3.Mesoglea serves as skeleton assist provides surface for the attachment of muscular processes and its elasticity helps in the extension of the body after contraction.
4.Trembleydiscovered that hydra has immense power of regeneration.Any piece of hydra will grow into an adultif it has a complete body wall and is not smaller than1.6mm in size.
5.Mating does not occur in hydra as it is hermaphrodite.
6.Zoochlorella is a symbiotic alga of hydra viridissima.
7.Interstitial
cells have the capacity to transform into other types of cells .Hence these are considered as reserve totipotent cells of hydra. According to BRIEN the hydra changes all the cells of its body within 45 days.
8.Hydra is a coelenterate in which division of labour has just started after poriferans.No coelom is found in it hence it is regarded as acoelomate.
9.Peneterants are the largest nematocysts which are used mainly for offence and defence.These are also called as stenoteles.
10.Thigmotaxis is the response to touch stimuli and is best shown by hydra.