Discuss the three pre‑zygotic reproductive isolation mechanisms that operate in plants. For each mechanism, give a specific example relevant to Indian flora.
Answer
Temporal isolation (e.g., *Lantana camara* flowers in summer while *Lantana indica* blooms in monsoon), Mechanical isolation (different corolla shapes of *Rhododendron arboreum* and *Rhododendron dalhousiae* prevent shared pollinators), and Gametic isolation (pollen of *Mimosa pudica* cannot fertilise *Mimosa diplotricha*).
Step-by-step solution
- Identify pre‑zygotic barriers that act before fertilisation in plants.
- Temporal isolation: flowering times differ; provide Indian example (*Lantana camara* vs *Lantana indica*).
- Mechanical isolation: morphological mismatch of floral parts; give example of two *Rhododendron* species with distinct corolla shapes.
- Gametic isolation: incompatibility between pollen and stigma; cite *Mimosa* species where pollen fails to germinate on the other’s stigma.
- Summarise that these barriers prevent hybrid formation and promote speciation.
Common mistake: Mixing pre‑zygotic with post‑zygotic mechanisms
Concept tested: Pre‑zygotic isolation in plants
Published · How this solution was prepared and checked
← All Organisms and Populations questions