Correct option is A
Protandry refers to the condition where the
male parts (anthers) of the flower
mature and shed pollen before the female parts (stigma) become receptive. This promotes
cross-pollination because when a flower's own stigma is ready, its own pollen is already gone.
Key Points:
·
Onion (Allium cepa):
· Exhibits
protandry.
· The anthers dehisce (release pollen)
before the stigma becomes receptive.
· This
temporal separation encourages
cross-pollination between different plants.
·
Pollinators, especially
bees, play a major role in transferring pollen from one flower to another in onions.
· Therefore, onions are classified as
highly cross-pollinated crops.
Other Options Explained:
·
(b) Radish:
· Radish exhibits
self-incompatibility, not mainly protandry.
·
(c) Cabbage:
· Cross-pollination mainly due to
self-incompatibility, not protandry.
·
(d) Cauliflower:
· Also relies on
self-incompatibility for cross-pollination rather than protandry.