Question

Based on your cladogram, from oldest to newest, in what order did the three characteristics (flowers, multicellularity, and xylem/ phloem) evolve? *The purple lines represent a characteristic change or adaptation.*

Answer 1

Complete question:

You will find the cladogram in the attached files

Answer:

• multicellularity
• xylem/phloem
• flowers

Explanation:  

Based on this cladogram, the order of changes was multicellularity, vascular system, flowers.

Multicellularity. The first division or point of divergence is located between moss and the rest of the organisms. Moss is included in the Bryophyta group, characterized for being the first terrestrial plants. They are not vascular plants, and their general structure is simple but pluricellular.  Multicellularity implicates association between different cells that specialized in accomplishing different functions. This complex association works to make the organism survive. Algae might be unicellular or pluricellular. Although is not the same, unicellular algae might form colonies, that are groups of cells agglomerated.

Xylem/ Phloem: The second change is related to the vascular system.  Cycads are gymnosperms. These are vascular plants that produce naked seeds. The vascular system developed by gymnosperms is very elaborated, with secondary growth, and including supporting cells that allow these plants to get bigger dimensions, particularly in height.  

Flowers: The last change is related to the emergence of flowers. Arabidopsis is included in the angiosperm group, the most evolved one, with great capabilities of reproduction and dispersion. They have flowers, which carry the reproductive structures. Once occurred fertilization,  fruits develop and carry the seeds. Flowers might be unisexual or hermaphrodites. Their vascular system is also very complex and adapted to different environments.