Roots are represented by root like structure called rhizoids in less developed lower plants (bryophytes and pteridophytes). The plant tissue system in these is not differentiated into true leaf, stem and roots as it is found in higher plants (gymnosperm and angiosperm).

Haplo diplontic type of life cycle is exhibited by Ectocarpus, Polysiphonia and Kelps. Here, diploid saprophytic phase alternate with haploid gametophytic phase. In Fucus, the main plant body is saprophytic and it shows diplontic type of life cycle.

In bryophytes the male sex organ is antheridium and female sex organ is archegonium. The gametophyte ( n ) in bryophyte bears the primiture sex organs in the form of antheridium (male) which produce flagellate antherozoids which are male gamete and need thin film of water to swim and reach female reproductive organ (archegonium).

Archegonia is female part which has single egg cell. Both these reproductive parts are born on male and female, anthridiophore and archegoniophores borne on haploid gametophyte.

Bryophytes are amphibian of plant kingdom. It is a group of primitive plant having a dominant gametophytic plant body. These plants can live in soil but depend on water for movement of male gametes called antherozoids to reach archegonium (female organ having egg cell) so that fertilisation can take place.

The structure are as given