31:03

Characters of phylum porifera and Classification

27:56

Conjugation in paramecium

28:09

Reproductive system of Sycon

10:13

Osmoregulation in paramecium

16:37

Reproduction and Osmoregulation in Euglena

21:46

Nervous system of pila

33:08

Structure of paramecium

30:19

Structure of Obelia