Q.14 Given below are two statements, one is labelled as Assertion (A) and other one
labelled as Reason (R).
Assertion (A) : APG classification system is not useful for adoption in herbaria
and flora
Reason (R) : APG system taxa have been classified only up to the level of family
In light of the above statements, choose the correct answer from the options given
below.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Here’s an SEO-friendly article tailored to your request, optimized for biology students and exam prep searches in molecular biology, taxonomy, and botany. I’ve incorporated the correct answer with a clear explanation of APG classification, why it’s actually useful for herbaria, and breakdowns of all options.

Understanding APG Classification in Taxonomy

The Angiosperm Phylogeny Group (APG) system revolutionizes plant classification using molecular data like DNA sequences, creating a phylogenetic framework for flowering plants (angiosperms). First published in 1998 and updated (e.g., APG IV in 2016), it prioritizes evolutionary relationships over traditional morphology-based systems.

This assertion-reason question tests your grasp of its practical applications, especially in herbaria (plant specimen collections) and floras (regional plant inventories). Let’s break it down.

The Question and Correct Answer

Assertion (A): APG classification system is not useful for adoption in herbaria and flora.
Reason (R): APG system taxa have been classified only up to the level of family.

Correct Answer: Option 4 – (A) is false but (R) is true.

Why This is Correct

• (R) is true: The core APG system deliberately classifies angiosperms only up to the family level. It defines ~64 orders and ~416 families based on cladistic (phylogenetic) evidence but stops short of genera or species. This modular design allows flexibility for lower taxa using other systems. For example, APG IV recognizes families like Asteraceae or Poaceae without delving into their thousands of species.

• (A) is false: Despite limiting to families, APG is highly useful for herbaria and floras. Modern herbaria (e.g., Kew Gardens, Smithsonian) and floras (e.g., Flora of North America) widely adopt APG for its accuracy in reflecting evolutionary history. Benefits include:

  • Stable, evidence-based family circumscriptions (e.g., merging or splitting families like Fabaceae).

  • Easier specimen organization via DNA-backed clades.

  • Integration with digital tools like barcoding for identification.

  Real-world adoption: India’s Botanical Survey uses APG-aligned classifications in updated floras.

(R) describes a limitation but doesn’t explain (A), as the family-level focus enhances usability, not hinders it.

Explanation of All Options

• Option 1: Both (A) and (R) true, (R) explains (A).
  Incorrect. (A) is false—APG is adopted in many herbaria despite family-only classification.

• Option 2: Both true, but (R) not explanation.
  Incorrect. Again, (A) fails because family-level detail suffices for practical use.

• Option 3: (A) true, (R) false.
  Incorrect. APG does limit to families, so (R) holds; (A) misrepresents utility.

• Option 4: (A) false, (R) true.
  Correct. Captures APG’s family focus as fact, while debunking the uselessness claim.

Quick Comparison: APG vs. Traditional Systems

Exam Tips for Assertion-Reason Questions

Focus on factual accuracy: Verify if Reason truly limits or enables the Assertion. For botany exams like NEET or CSIR-NET, memorize APG updates—family ranks are stable, aiding quick reference.