Pteridophytes (The First Vascular Plants) NCERT Line to Line for NEET 2026 Notes

🌿 Topic: Pteridophytes (The First Vascular Plants)

Students who prefer video explanation can watch the lecture first. NCERT-based notes are given below.

1. Introduction & General Characteristics

• Groups Included: Pteridophytes include Horsetails and Ferns.
• Economic Importance:
  • Used for medicinal purposes.
  • Used as soil binders.
  • Frequently grown as ornamentals.
• Evolutionary Significance: They are the first terrestrial plants to possess vascular tissues (xylem and phloem).
• Habitat:
  • Found in cool, damp, shady places.
  • Some may flourish well in sandy-soil conditions.

2. Plant Body (Sporophyte)

• Dominant Phase: In Pteridophytes, the main plant body is a Sporophyte (unlike Bryophytes where it is a Gametophyte).
• Differentiation: It is differentiated into true root, stem, and leaves.
• Vascular Tissues: These organs possess well-differentiated vascular tissues.
• Leaves: The leaves in Pteridophyta are of two types:
  1. Microphylls: Small leaves (e.g., Selaginella).
  2. Macrophylls: Large leaves (e.g., Ferns).

3. Spore Formation & Structures

• Sporangia: The sporophytes bear sporangia that are subtended by leaf-like appendages called sporophylls.
• Strobili / Cones: In some cases, sporophylls may form distinct compact structures called strobili or cones.
  • NCERT Examples: Selaginella, Equisetum.
• Meiosis: The sporangia produce spores by meiosis in spore mother cells.

4. The Gametophyte (Prothallus)

• Germination: The spores germinate to give rise to:
  • Inconspicuous, small, multicellular,
  • Free-living,
  • Mostly photosynthetic thalloid gametophytes called Prothallus.
• Growth Requirements: Prothallus requires cool, damp, shady places to grow.
• Geographical Restriction: Because of this specific restricted requirement and the need for water for fertilization, the spread of living pteridophytes is limited and restricted to narrow geographical regions.

5. Sexual Reproduction

• Sex Organs: The gametophytes bear male and female sex organs called antheridia and archegonia, respectively.
• Fertilization Process:
  1. Water is required for the transfer of antherozoids (male gametes released from antheridia) to the mouth of the archegonium.
  2. Fusion of the male gamete with the egg present in the archegonium results in the formation of the Zygote.
• Post-Fertilization: Zygote produces a multicellular well-differentiated sporophyte (the dominant phase).

6. Homospory vs. Heterospory (⭐⭐ High Yield)

This is the most critical section for NEET.

A. Homosporous

• Majority of the pteridophytes produce all spores of similar kinds.
• Such plants are called homosporous.

B. Heterosporous

• Genera like Selaginella and Salvinia produce two kinds of spores:
  1. Macro (large) spores.
  2. Micro (small) spores.
• Such plants are known as heterosporous.

C. Development in Heterosporous Plants (Seed Habit)

1. Megaspores germinate into female gametophytes.
2. Microspores germinate into male gametophytes.
3. Retention: The female gametophytes in these plants are retained on the parent sporophytes for variable periods.
4. Embryo Development: The development of the zygotes into young embryos takes place within the female gametophytes.
5. Evolutionary Significance: This event is a precursor to the seed habit, considered an important step in evolution.

7. Classification of Pteridophytes

NCERT classifies Pteridophytes into four classes. You must memorize the examples for each.

8. Quick Review: NCERT Key Terms

• Prothallus: The free-living, photosynthetic gametophyte of Pteridophytes.
• Strobilus: Compact structure formed by sporophylls (found in Selaginella, Equisetum).
• Microphylls: Small leaves (Selaginella).
• Macrophylls: Large leaves (Ferns).
• Precursor to Seed Habit: Retention of female gametophyte on parent sporophyte (Selaginella, Salvinia).

Comparison: Bryophytes vs. Pteridophytes