Answer: Identification of organisms based on contrasting characters.
- A Storing dried plant specimens mounted on herbarium sheets
- B Identification of organisms based on contrasting characters
- C Cultivating living plant specimens under controlled greenhouse conditions
- D Preserving animal specimens in formalin solution within museums
Correct answer: B. Identification of organisms based on contrasting characters
Explanation: A key helps identify organisms by presenting paired contrasting characters (couplets) that the user chooses between step by step.
The taxonomic hierarchy narrows from Kingdom (broadest, covering the most organisms but fewest shared traits) down to Species (narrowest, fewest organisms but most shared traits) - every level in between is a progressively more specific subset of the one above it.
Concept context
Biodiversity, taxonomy, binomial nomenclature, the taxonomic hierarchy, and taxonomic aids like herbaria and botanical gardens. The foundational first chapter of NCERT Biology.