Q.12 Free central placentation is present in the family of
1. Brassicaceae
2. Cucurbitaceae
3. Caryophyllaceae
4. Capparaceae
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Free Central Placentation Family: MCQ Answer & Detailed Placentation Guide
In flowering plants (angiosperms), placentation refers to the arrangement of ovules within the ovary, a key feature for identifying plant families in botany exams. Free central placentation occurs when ovules develop on a central column in a single-chambered ovary, unconnected to the ovary walls—like a “free-standing pillar” of ovules.
Correct Answer: Caryophyllaceae (Option 3)
Caryophyllaceae (pink or carnation family) exhibits free central placentation. Examples include Dianthus (carnation) and Silene. The ovary is unilocular (single chamber) with ovules borne on a central axis raised from the ovary base, not fused to the walls. This matches the classic definition and is a high-yield fact for exams.
(Visual: Ovules on a free central column in Caryophyllaceae ovary.)
Why Not the Other Options? Placentation Breakdown
Let’s compare all options with clear diagrams and examples to solidify your understanding:
Brassicaceae (Option 1) – Parietal Placentation
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Family of mustard (Brassica) and cabbage.
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Ovary is bilocular (two chambers) due to a false septum (replum).
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Ovules attach to the ovary walls (parietal placentation).
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Not free central—walls are involved.
Cucurbitaceae (Option 2) – Parietal Placentation
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Family of cucumber, pumpkin, and bottle gourd.
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Ovary is unilocular but with parietal placentation: ovules on 3–5 elongated parietal placente protruding inward.
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Syncarpous gynoecium forms a single fruit.
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Not free central—ovules stick to walls, not a free column.
Capparaceae (Option 4) – Parietal or Axile Placentation
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Family of caper (Capparis).
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Typically parietal placentation in a unilocular ovary, sometimes multi-locular.
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Closely related to Brassicaceae but lacks the free central setup.
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Not free central.
| Family | Placentation Type | Ovary Chambers | Key Examples |
|---|---|---|---|
| Brassicaceae | Parietal (bilocular) | 2 | Mustard, Cabbage |
| Cucurbitaceae | Parietal | 1 | Cucumber, Pumpkin |
| Caryophyllaceae | Free Central | 1 | Carnation, Chickweed |
| Capparaceae | Parietal/Axile | 1–many | Caper |
Exam Tips for Placentation MCQs
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Mnemonic for Free Central: “CaRyophyllaceae’s Free Column” (Caryophyllaceae).
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Differentiate from axile (ovules on central axis in multi-chambered ovary, e.g., Solanaceae).
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Practice with NEET/UGC-NET questions—placentation often pairs with floral formula (Caryophyllaceae: ⊕ ⚥ P_{4-5} A_{4-5} G_{(2)}).
Mastering placentation boosts your botany score. Search “free central placentation family” for more MCQs!