(A) Micropyle
(B) Chalaza
(C) Funiculus
(D) Hilum
Ovule anatomy questions test fundamental plant reproductive morphology critical for seed development and angiosperm classification. The ovule, containing the embryo sac, connects to the placenta (ovary wall tissue) via a specialized stalk that delivers nutrients and positions the ovule optimally for pollination.
The correct answer is (C) Funiculus, the stalk-like structure tethering each ovule to the placental surface in the ovary locule.
Why (C) Funiculus is the Ovule’s Placental Stalk
Funiculus (also called funicle) serves as the vascular connection between placenta and ovule body, transporting water, sugars, and hormones. Its length varies by placentation type (axile, parietal, basal). In mature seeds, funiculus becomes the seed stalk (pedicel). Hilum marks the funiculus-ovule fusion point.
Complete Ovule Anatomy Breakdown
| Option | Structure | Function | Relation to Placenta Stalk? |
|---|---|---|---|
| (A) Micropyle | Small pore in integuments | Pollen tube entry for fertilization | Opening, not stalk |
| (B) Chalaza | Basal ovule region | Vascular connection to funiculus | Tissue junction, not stalk |
| (C) Funiculus | Stalk attaching ovule to placenta | Nutrient transport | Correct |
| (D) Hilum | Scar where funiculus attaches to ovule | Attachment point | Junction site, not stalk itself |
Explanation of All Options
-
(A) Micropyle
Incorrect. Small opening at ovule apex formed by integument gap. Enables pollen tube entry during double fertilization. -
(B) Chalaza
Wrong. Broad basal region where funiculus vascular bundles enter nucellus. Opposite micropyle end. -
(C) Funiculus
Correct. Stalk connecting ovule body to placenta. Primary nutrient highway during seed development. -
(D) Hilum
No. Junction/scar where funiculus fuses with ovule integuments. Visible on mature seeds (e.g., bean hilum).
Ovule-Placenta Attachment Visualized
Placenta (ovary wall)
|
Funiculus (stalk) ← **ANSWER**
|
Hilum (junction)
|
Chalaza (base)
|
Nucellus + Embryo sac
^
Micropyle (apex opening)
Biotech relevance: Funiculus anatomy determines seed yield in crop breeding. Abnormal placentation reduces ovule fertility. Memory trick: “Funiculus = Fun connection to placenta.” Hilum confusion common—hilum is the funiculus’s footprint on ovule surface.
