Why are green algae considered to be an ancestral to plants? ?They are considered to be an ancestral to plants because both they both reproduce chlorophyll a/b, both have cell walls made od cellulose. ?Because in conjugation DNA is being shared between one cell to other without actually reproducing.Click to see full answer. Correspondingly, are algae the ancestors of plants?Ancestors of land plants revealed. However, new research shows that the closest relatives to land plants are actually conjugating green algae such as Spirogyra. It was previously thought that land plants evolved from stonewort-like algae.Likewise, which algae is most closely related to plants? Green algae are the algae most closely related to plants. Also know, how did plants evolve from algae? Algae do not keep the embryo inside of themselves but release it into water. This was the first feature to evolve that separated plants from green algae. This is also the only adaptation shared by all plants. Over time, plants had to evolve from living in water to living on land.What evidence led scientists to think that green algae were the ancestors of plants?3: What evidence led scientists to think that green algae were the ancestors of plants. Scientists have found that plants and green algae contain the same form of chlorophyll.