Which of the following is the correct order of plant species from higher to lower order ?

Question

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Correct — D, Plant Kingdom – Phylum – Class – Order. Biological classification is a nested hierarchy of ranks running Kingdom → Phylum (called Division in botany) → Class → Order → Family → Genus → Species. Each rank sits wholly inside the one above it: a Kingdom contains several Phyla/Divisions, each Phylum contains several Classes, each Class contains several Orders, and so on. So reading from the highest (most inclusive) category downwards, the only sequence that respects the nesting is Plant Kingdom, then Phylum, then Class, then Order. For a plant such as wheat the chain runs Kingdom Plantae → Division/Phylum Angiospermae (flowering plants) → Class Monocotyledonae → Order Poales, and only then Family Poaceae, Genus Triticum, species Triticum aestivum.

Why the other options are wrong — (a) It puts the most inclusive category, the Plant Kingdom, at the bottom and starts from Class — the exact inversion of what the question asks. It also breaks the internal nesting, since Phylum can never sit below Class.  (b) This is a perfectly valid hierarchy but read in the wrong direction — it goes from the lower (narrower) rank to the higher one. The question explicitly asks for higher to lower, so this is the classic 'right ladder, wrong end' trap.  (c) It inserts the Plant Kingdom between Class and Phylum, which is impossible: the Kingdom is the widest category of the four and must contain the Phylum, which in turn contains the Class.

Concept: Taxonomy arranges organisms into taxonomic categories (ranks) of decreasing inclusiveness — Kingdom, Phylum/Division, Class, Order, Family, Genus, Species. As you move down the ladder, the number of characters shared by the members of a group increases while the number of organisms in the group falls; moving up, groups get larger but share fewer common features. The scheme descends from Carl Linnaeus, who also gave botany its binomial system of naming (Genus + species).

State PCS 2024 Q12 — Science & Technology PYQ with Answer

State PCS 2024 Q12 — Science & Technology PYQ with Answer