AP BIOLOGY

Detailed explanation-1: -The liverwort Marchantia is strictly dioecious. Noll showed in 1907 that the spores consist of two classes, those which grow into male plants and those which grow into female plants. Both types of spores are produced in the same sporangium.

Detailed explanation-2: -Marchantia polymorpha is a dioecious species having male and female organs on different thalli. Female and male gametangia, known as the ‘archegonium’ (plural: archegonia) and ‘antheridium’ (plural: antheridia), are produced on the umbrella-like sexual branches of the female and male thalli, respectively.

Detailed explanation-3: -Just as in Marchantia polymorpha, the developing sporophyte is then surrounded by the old wall of the archegone, the calyptra, a sheath, the perianth, and the involucre, which incloses the whole group of archegonia and developing sporophytes beneath each lobe.

Detailed explanation-4: -Marchantia have two ways of reproducing-sexually (during their sporophytic phase) and asexually (during their gametophytic phase). In their gametophytic phase, the plant produces gemma cups which contain gemmae, haploid spores which, when dispersed by wind or rain, has the ability to create a clone of its parent.