Answer: Isolated metabolic reactions in cell-free extracts are not considered alive.
- A Metabolism is restricted to multicellular organisms, not unicellular ones
- B Isolated metabolic reactions in cell-free extracts are not considered alive
- C Non-living matter typically shows a faster metabolic rate than living matter
- D Metabolism occurs in plants but is absent in most animal cells
Correct answer: B. Isolated metabolic reactions in cell-free extracts are not considered alive
Explanation: Cell-free systems can perform many individual biochemical reactions in a test tube, but such isolated reactions occurring outside the body are not considered an indicator of life on their own.
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.