Which of the following sequences is the correct evolutionary trend in plants?

Analyze the question: The question asks for the order in which plant groups evolved, from the most primitive to the most advanced.

Explain the concept: Plants evolved from aquatic ancestors (green algae) and gradually adapted to life on land.

• Algae: simple, aquatic, with no true roots, stems or leaves. They are the most primitive group.
• Bryophytes (liverworts and mosses): the first land plants. They have no vascular tissue (no xylem or phloem), so they stay small and need moisture for reproduction.
• Pteridophytes (ferns): they have vascular tissue, true roots, stems and leaves, but still reproduce with spores and need water for fertilisation.
• Gymnosperms, then angiosperms: these come later, with seeds and then flowers and fruits.

Show the solution:

1. Start with the most primitive group, which is algae (aquatic, simple body).
2. Next come the bryophytes. Liverworts are generally considered more primitive than mosses, so the order is liverworts, then mosses.
3. Ferns follow, because they are the first group with vascular tissue.

The sequence is therefore: Algae → liverworts → mosses → ferns.

Check the other options:

• B puts algae last, which is wrong because algae are the ancestors.
• C puts mosses before algae, which is wrong.
• D starts with ferns, which are more advanced than the bryophytes, so it reverses the trend.

Exam tip: Remember the order "A-B-P-G-A": Algae, Bryophytes, Pteridophytes, Gymnosperms, Angiosperms. It goes from simple and aquatic to complex and land-adapted.