Answer
a) nonvascular plants
b) vascular seedless plants
c) gymnosperms
d) angiosperms
1) evolution of cuticles, multicellular gametangia, and multicellular embryos
2) evolution of vascular tissue
3) evolution of seeds
Work Step by Step
The first plants that originated from algal ancestors are the nonvascular plants or bryophytes, which lack true roots and leaves. Evolving from these plants are the vascular seedless plants that are supported by the lignin-hardened vascular tissues they posses. Some vascular plants then developed seeds that improved their ability to reproduce and increase diversity, namely gymnosperms and angiosperms. Angiosperms are the most recent branch in plant evolution as they possess flowers, which are absent in gymnosperms.
