Question

Differentiate between wind-pollinated and insect-pollinated flowers. Give an example of each type.

Hint:

Compare size and colour, scent and nectar, pollen type and stigma; examples: maize and Salvia.

Answer 1

Step 1: Understanding the Concept:
Pollination needs an agent that carries pollen from anther to stigma. The flower is built to suit its agent, so wind and insect flowers differ in many traits.

Step 2: Differences (wind-pollinated flowers):
1. The flowers are small, colourless, and have no scent or nectar.
2. The pollen grains are light, dry, non-sticky and produced in huge numbers.
3. The stigma is large, feathery and hangs out to catch pollen from the air.
4. The ovary often has a single ovule, and many flowers sit in a tight inflorescence, as in a corn cob.

Step 3: Differences (insect-pollinated flowers):
1. The flowers are large, brightly coloured, scented and offer nectar or pollen as a reward.
2. The pollen grains are sticky or spiny, so they cling to the insect body.
3. The stigma is small and sticky.
4. Pollen is produced in smaller amounts, and the ovary may hold many ovules.

Step 4: Examples:
Wind-pollinated: maize, wheat, other grasses, date palm.
Insect-pollinated: Salvia, rose, Yucca, Amorphophallus.

Final Answer:
Wind flowers are small and dull with light pollen and feathery stigma (example: maize). Insect flowers are showy and scented with sticky pollen and a small sticky stigma (example: Salvia).