Cycas is an evergreen , palm like small tree. It grows in xerophytic habitats. The sporophytic plant body of Cycas is differentiated into roots, stem and leaves. The roots are of two types : Normal tap roots and coralloid roots. The leaves are also of two types i.e. dimorphic . The assimilatory leaves or foliage leaves and Scale leaves . The asexual reproduction takes place by the formation of sporangia and spores . The sporangia are arranged on the lower side of the microsporophyll in definite groups called sori. Sexual reproduction occurs by the formation of antheridia and archegonia.

Ectocarpus is a marine alga. The thallus is heterotrichous. It consists of a prostrate rhizoidal system and an erect branched system . The main pigment is xanthophyll. The cytoplasm contains polyphenol containing vacuoles called physodes. The asexual reproduction occurs by the formation of zoospores in two types of sporangia called unilocular sporangia and plurilocular sporangia. The sexual reproduction occurs by isogamy , morphological anisogamy and physiological anisogamy. In physiological anisogamy the male gametes are more active than the female gamete. Ectocarpus is a brown alga and shows Isomorphic alternation of generation.