Question

Which of the following is the best explanation for the excurrent (pyramidal) shape of Pinus (the branches giving the plant the appearance of a tall cone)?

• A. Competition among adjoining trees for sunlight
• B. The effect of auxins on growth of stem tips
• C. Adaptation for wind pollination
• D. Efficiency of water transport from ground to leaves

Answer 1

The correct option is C Adaptation for wind pollination

Wind pollination (anemophily) in gymnosperms is thought to be an ancestral state. Extensive diversity of male reproductive structures within gymnosperms represents an evolutionary response to long-term selection and results in solutions to the physical restraints of anemophily.

Anemophilous plants possess well-exposed stamens, so that the pollens are exposed to wind currents and also have large and feathery stigma to easily trap airborne pollen grains.