Question

Plants I

1. Your parents are fascinated to learn about bryophytes and pteridophytes. What are at least two traits that they have in common? What are at least two traits that are different between them? How could your parents tell the difference between a bryophyte or pteridophyte if they saw one on a hike?

3. You see a beautiful fern and notice the underside of the frond is dotted with brown/yellow points. Upon closer inspection those points flinging stuff away from the frond! What are these points called, what are they flinging, and why are they doing it?

Answer 1

Answer :

1)

Bryophytes are non-vascular plants i.e. do not contain xylem and phloem tissues.

Eg : Liverworts, hornworts, and mosses .

Pteridophytes are termed as vascular plants as they contain xylem and phloem tissues.

Eg : ferns

Common traits of bryophytes and pteridophytes :

1) Both have the heteromorphic alternation of generations.

2) Sexual reproduction Oogamous type .

3) Presence of Multicellular sporangia .

4) Flagellated male gametes while female non-motile.

​​​​​​Traits that are different between Bryophytes and Pteridophytes :

1) Bryophytes has leafy or thalloid plant body, while in Pteridophytes plant body in differentiated into roots, stems, and leaves.

​​ 2) No roots are present in bryophytes instead rhizoids are present; In pteridophytes roots are present.

3) Cells are haploid type in bryophyte, and diploid cells are present in pteridophytes .

4) In bryophytes, the gametophyte is dominating whereas saprophytes are dominating in pteridophytes .

2)

Parents tell the difference between a bryophyte or pteridophyte if they saw one on a hike based on their external morphology .

​​​​​​3)

Brown / Yellow spots in a regular pattern on the underside of a fern leaf are usually spore cases.

Brown / Yellow spots on the underside of a fern leaf are probably just a sign the fern is ready to reproduce.

Fern reproduction is a two-stage process.

In the first stage, ferns produce spores, tiny dust-like particles in brown / yellow spore cases on the undersides of their leaves. When the spore cases mature, they open and release the spores, which fall to the soil. The spores sprout and grow into small, heart-shaped plants.

In the second stage of fern reproduction, these small plants release male or female cells. When male and female cells meet, they form an embryo, which develops into a fern plant.

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