Several groups of organisms are exclusively photosynthetic and are known as algae or plants. Examples include Brown Algae, Red Algae, Charophytes, Chlorophytes*, and the Embryophytes (nonvascular plants, seedless vascular plants, seed plants). These photosynthetic organisms are highly variable in life cycle. Some are haplontic and others have alternation of generations. Among those with alternation of generations some are homosporous and others are heterosporous. Another type of variation among those alternation of generations is the relative size of the gametophyte and sporophyte. Draw a phylogeny of the following groups of the Archiplastida: red algae, charophytes, mosses, lycophytes, pterophytes, gymnosperms, angiosperms. Mark on the phylogeny at least six evolutionary transitions in life cycle. What are some advantages and disadvantages of being homosporous vs heterosporous (give 2) What is an advantage of having a dominant sporophyte (diploid) stage? Brown algae usually have an alternation of generations life cycle. They are similar in structure but very distantly related (separate evolution of photosynthesis) to the Embryophytes. What can you conclude from this information?.