Give reasons for the following:
$(i)$ Bryophytes are called amphibians of the plant kingdom.
$(ii)$ From phylum Platyhelminthes onwards,animals are categorized as 'triploblastic.'
$(iii)$ The presence of 'coelom' in an animal's body is considered advantageous.

(N/A) $(i)$ Bryophytes are called amphibians of the plant kingdom because,like amphibians,they require water for fertilization. Their motile male gametes (antherozoids) need an aqueous medium to swim to the female gametes (egg).
$(ii)$ Animals from phylum Platyhelminthes onwards possess three germ layers: ectoderm,mesoderm,and endoderm. This 'triploblastic' condition allows for the development of complex,differentiated tissues and organs,providing a higher degree of body organization.
$(iii)$ The coelom is a true internal body cavity lined by mesoderm. It is advantageous because it provides space for the development and protection of well-developed internal organs,allowing them to grow and function independently of the body wall.