Module: | Double Fertilization & Endosperm
Q67: Consider the following statements regarding seed dispersal mechanisms:
1. Seeds of plants like Xanthium and Urena are adapted for zoochory, possessing stiff hooks and spines to attach to animal fur.
2. The Asteraceae family utilizes anemochory, where the calyx is heavily modified into a hairy, parachute-like structure known as the pappus.
3. Autochory is a mechanism where seeds are passively transported over massive distances by flowing river currents.
Which of the above statements is/are correct?
2. The Asteraceae family utilizes anemochory, where the calyx is heavily modified into a hairy, parachute-like structure known as the pappus.
3. Autochory is a mechanism where seeds are passively transported over massive distances by flowing river currents.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, while Statement 3 is incorrect.
Seed dispersal is an evolutionary imperative to prevent overcrowding and reduce resource competition among offspring.
Plants utilize various vectors.
Zoochory relies on animals; structurally, Xanthium (cocklebur) fruits have hooked spines that tangle in animal coats, ensuring wide geographical spread.
Anemochory relies on wind; in sunflowers and dandelions (Asteraceae), the sepals (calyx) evolve into a feathery pappus that acts as a highly efficient aerodynamic parachute.
Statement 3 confuses the terminology.
Hydrochory is the dispersal of seeds by water (e.g., the fibrous mesocarp of the coconut allowing it to float). Autochory, conversely, is a self-dispersal mechanism.
It involves explosive, mechanically active fruit dehiscence (as seen in the squirting cucumber or touch-me-not), where physical tension causes the fruit to burst and shoot seeds locally, not via water currents.
Seed dispersal is an evolutionary imperative to prevent overcrowding and reduce resource competition among offspring.
Plants utilize various vectors.
Zoochory relies on animals; structurally, Xanthium (cocklebur) fruits have hooked spines that tangle in animal coats, ensuring wide geographical spread.
Anemochory relies on wind; in sunflowers and dandelions (Asteraceae), the sepals (calyx) evolve into a feathery pappus that acts as a highly efficient aerodynamic parachute.
Statement 3 confuses the terminology.
Hydrochory is the dispersal of seeds by water (e.g., the fibrous mesocarp of the coconut allowing it to float). Autochory, conversely, is a self-dispersal mechanism.
It involves explosive, mechanically active fruit dehiscence (as seen in the squirting cucumber or touch-me-not), where physical tension causes the fruit to burst and shoot seeds locally, not via water currents.