MyCompetitiveExams Logo MyCompetitiveExams
MyCompetitiveExams Logo MyCompetitiveExams
Search 1,140+ Questions
Chapters, formulas, speed tricks
→
⚡ Brahmastra NEET 2027
720 MARKS

Dynamic 180-question full-length simulator mixed dynamically from all 6 years for 2027 & 2026 aspirants.

Launch Brahmastra 2027 Test →
Start Practice →
100% Free · No Login Required
Q.101 Botany ⭐ 360° Option Elimination Active
Vault ↗

NEET 2023 Botany Question 101 Solution

Topic: Plant Kingdom · Official NTA Booklet Code G5
NEET 2023 Botany Question 101: Heterospory and Seed Habit Precursor

Question

Identify the pair of heterosporous pteridophytes among the following:

  1. (1)Equisetum and Salvinia
  2. (2)Lycopodium and Selaginella
  3. (3)Selaginella and Salvinia
  4. (4)Psilotum and Salvinia
✓
Verified Against NTA Final Answer Key
Option (3) : Selaginella and Salvinia
📚 Plant Kingdom Easy
📋 Given Parameters & Problem Setup
Plant Group Pteridophytes (Vascular Cryptogams)
Spore Type Heterosporous (two distinct kinds of spores)
⚡

The 30-Second Exam Hall Shortcut: ⚡ Heterospory Mnemonic Anchor: "Double S" = Selaginella & Salvinia

⏱️ Save ~25 seconds

Majority of pteridophytes are homosporous. The classic heterosporous genera highlighted in NCERT are Selaginella and Salvinia (along with Marsilea and Azolla). Look for the "Double S" pair for an instant 5-second answer!

1 Recall that most pteridophytes produce identical spores (homosporous, e.g., Equisetum, Lycopodium, Dryopteris, Psilotum).
2 Pteridophytes producing two kinds of spores—macro (mega) and microspores—are heterosporous.
3 NCERT canonical heterosporous genera: Selaginella and Salvinia.
4 Option (3) groups Selaginella and Salvinia together.
🛡️
Why You Can 100% Trust This Shortcut: Canonical NCERT Plant Kingdom taxonomy on Pteridophytes and origin of seed habit.
📐

Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

Definition of Heterospory in Pteridophytes

Heterospory is the condition of producing two morphologically distinct types of spores differing in size and sexual differentiation:

Heterospory  ⟺  {Microspores⟶Male gametophyteMegaspores⟶Female gametophyte\text{Heterospory} \iff \begin{cases} \text{Microspores} & \longrightarrow \text{Male gametophyte} \\[4pt] \text{Megaspores} & \longrightarrow \text{Female gametophyte} \end{cases}
Step 2

Classification of Common Pteridophytic Genera

Pteridophytes are classified based on spore type as follows:

Homosporous:Psilotum, Lycopodium, Equisetum, Dryopteris, Pteris, AdiantumHeterosporous:Selaginella, Salvinia, Marsilea, Isoetes, Azolla\begin{aligned} \text{\textbf{Homosporous:}} & \quad \textit{Psilotum, Lycopodium, Equisetum, Dryopteris, Pteris, Adiantum} \\[4pt] \text{\textbf{Heterosporous:}} & \quad \textit{Selaginella, Salvinia, Marsilea, Isoetes, Azolla} \end{aligned}
Step 3

Evolutionary Significance

The retention of the megaspore within the megasporangium on the parent sporophyte in heterosporous pteridophytes like Selaginella and Salvinia represents the crucial evolutionary precursor to the seed habit in spermatophytes.

⭐

360° Option Elimination Engine Key Feature

Diagnose every choice: Know exactly why the right option works and why distractors fail.

4-Option Deep Scan
1 1
✗ Incorrect
Verdict & Scientific Reason:

Mismatched pair: Salvinia is heterosporous, but Equisetum (horsetail) is homosporous.

⚠️
Student Fallacy (Why candidates pick this trap): Confusing horsetails (Equisetum) with heterosporous water ferns.
2 2
✗ Incorrect
Verdict & Scientific Reason:

Mismatched pair: Selaginella is heterosporous, but Lycopodium (club moss) is homosporous.

⚠️
Student Fallacy (Why candidates pick this trap): Assuming all lycophytes share the same spore condition; Lycopodium is strictly homosporous.
3 3
✓ 100% Correct
Verdict & Scientific Reason:

Both genera produce microspores and megaspores, matching NCERT criteria verbatim.

💡
Why this is airtight: None; canonical textbook identification.
4 4
✗ Incorrect
Verdict & Scientific Reason:

Mismatched pair: Salvinia is heterosporous, but Psilotum is a primitive homosporous whisk fern.

⚠️
Student Fallacy (Why candidates pick this trap): Failing to eliminate primitive homosporous Psilotales.
⚠️

NTA Trap Alert: Lycopodium vs. Selaginella Spore Confusion

Lycophytes contain both Lycopodium and Selaginella. Students frequently confuse the two, forgetting that Lycopodium is homosporous while Selaginella is heterosporous.

🛡️ How to avoid the -1 mark: Use the mnemonic "SLS": Selaginella is Heterosporous, Lycopodium is Homosporous.
📖

Core NEET Syllabus Standard

NCERT Biology · Plant Kingdom Standard Benchmark
Core Scientific Principle Tested:

"Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous."

Syllabus Focus: Pteridophytes
✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

Ready to attempt under real exam pressure?

Test your speed and accuracy in the authentic 200-minute timed NTA simulator.

Launch NEET 2023 CBT Test →

Spotted a mistake in this solution? Report an error (support@mycompetitiveexams.com)

⚖️ Legal & Fair Dealing Notice: Sourced from publicly released NEET 2023 question papers and NEET answer keys for private study, research, and non-commercial educational practice under Fair Dealing (Section 52(1)(a) of the Indian Copyright Act, 1957). Not affiliated with or endorsed by NTA or NMC.

Solve 4 NEET Questions a Day — One per Subject

Cover all 1,140 official NEET questions in 285 days at your own pace. Progress is saved on your device. No login needed.